Chapter
stringclasses
18 values
sentence_range
stringlengths
3
9
Text
stringlengths
7
7.34k
1
1990-1993
Rationalised 2023-24 Physics 66 In an external electric field, the positive and negative charges of a non- polar molecule are displaced in opposite directions The displacement stops when the external force on the constituent charges of the molecule is balanced by the restoring force (due to internal fields in the molecule) The non-polar molecule thus develops an induced dipole moment The dielectric is said to be polarised by the external field
1
1991-1994
The displacement stops when the external force on the constituent charges of the molecule is balanced by the restoring force (due to internal fields in the molecule) The non-polar molecule thus develops an induced dipole moment The dielectric is said to be polarised by the external field We consider only the simple situation when the induced dipole moment is in the direction of the field and is proportional to the field strength
1
1992-1995
The non-polar molecule thus develops an induced dipole moment The dielectric is said to be polarised by the external field We consider only the simple situation when the induced dipole moment is in the direction of the field and is proportional to the field strength (Substances for which this assumption is true are called linear isotropic dielectrics
1
1993-1996
The dielectric is said to be polarised by the external field We consider only the simple situation when the induced dipole moment is in the direction of the field and is proportional to the field strength (Substances for which this assumption is true are called linear isotropic dielectrics ) The induced dipole moments of different molecules add up giving a net dipole moment of the dielectric in the presence of the external field
1
1994-1997
We consider only the simple situation when the induced dipole moment is in the direction of the field and is proportional to the field strength (Substances for which this assumption is true are called linear isotropic dielectrics ) The induced dipole moments of different molecules add up giving a net dipole moment of the dielectric in the presence of the external field A dielectric with polar molecules also develops a net dipole moment in an external field, but for a different reason
1
1995-1998
(Substances for which this assumption is true are called linear isotropic dielectrics ) The induced dipole moments of different molecules add up giving a net dipole moment of the dielectric in the presence of the external field A dielectric with polar molecules also develops a net dipole moment in an external field, but for a different reason In the absence of any external field, the different permanent dipoles are oriented randomly due to thermal agitation; so the total dipole moment is zero
1
1996-1999
) The induced dipole moments of different molecules add up giving a net dipole moment of the dielectric in the presence of the external field A dielectric with polar molecules also develops a net dipole moment in an external field, but for a different reason In the absence of any external field, the different permanent dipoles are oriented randomly due to thermal agitation; so the total dipole moment is zero When an external field is applied, the individual dipole moments tend to align with the field
1
1997-2000
A dielectric with polar molecules also develops a net dipole moment in an external field, but for a different reason In the absence of any external field, the different permanent dipoles are oriented randomly due to thermal agitation; so the total dipole moment is zero When an external field is applied, the individual dipole moments tend to align with the field When summed overall the molecules, there is then a net dipole moment in the direction of the external field, i
1
1998-2001
In the absence of any external field, the different permanent dipoles are oriented randomly due to thermal agitation; so the total dipole moment is zero When an external field is applied, the individual dipole moments tend to align with the field When summed overall the molecules, there is then a net dipole moment in the direction of the external field, i e
1
1999-2002
When an external field is applied, the individual dipole moments tend to align with the field When summed overall the molecules, there is then a net dipole moment in the direction of the external field, i e , the dielectric is polarised
1
2000-2003
When summed overall the molecules, there is then a net dipole moment in the direction of the external field, i e , the dielectric is polarised The extent of polarisation depends on the relative strength of two mutually opposite factors: the dipole potential energy in the external field tending to align the dipoles with the field and thermal energy tending to disrupt the alignment
1
2001-2004
e , the dielectric is polarised The extent of polarisation depends on the relative strength of two mutually opposite factors: the dipole potential energy in the external field tending to align the dipoles with the field and thermal energy tending to disrupt the alignment There may be, in addition, the ‘induced dipole moment’ effect as for non-polar molecules, but generally the alignment effect is more important for polar molecules
1
2002-2005
, the dielectric is polarised The extent of polarisation depends on the relative strength of two mutually opposite factors: the dipole potential energy in the external field tending to align the dipoles with the field and thermal energy tending to disrupt the alignment There may be, in addition, the ‘induced dipole moment’ effect as for non-polar molecules, but generally the alignment effect is more important for polar molecules Thus in either case, whether polar or non-polar, a dielectric develops a net dipole moment in the presence of an external field
1
2003-2006
The extent of polarisation depends on the relative strength of two mutually opposite factors: the dipole potential energy in the external field tending to align the dipoles with the field and thermal energy tending to disrupt the alignment There may be, in addition, the ‘induced dipole moment’ effect as for non-polar molecules, but generally the alignment effect is more important for polar molecules Thus in either case, whether polar or non-polar, a dielectric develops a net dipole moment in the presence of an external field The dipole moment per unit volume is called polarisation and is denoted by P
1
2004-2007
There may be, in addition, the ‘induced dipole moment’ effect as for non-polar molecules, but generally the alignment effect is more important for polar molecules Thus in either case, whether polar or non-polar, a dielectric develops a net dipole moment in the presence of an external field The dipole moment per unit volume is called polarisation and is denoted by P For linear isotropic dielectrics, 0 P=ε χ eE (2
1
2005-2008
Thus in either case, whether polar or non-polar, a dielectric develops a net dipole moment in the presence of an external field The dipole moment per unit volume is called polarisation and is denoted by P For linear isotropic dielectrics, 0 P=ε χ eE (2 37) where ce is a constant characteristic of the dielectric and is known as the electric susceptibility of the dielectric medium
1
2006-2009
The dipole moment per unit volume is called polarisation and is denoted by P For linear isotropic dielectrics, 0 P=ε χ eE (2 37) where ce is a constant characteristic of the dielectric and is known as the electric susceptibility of the dielectric medium It is possible to relate ce to the molecular properties of the substance, but we shall not pursue that here
1
2007-2010
For linear isotropic dielectrics, 0 P=ε χ eE (2 37) where ce is a constant characteristic of the dielectric and is known as the electric susceptibility of the dielectric medium It is possible to relate ce to the molecular properties of the substance, but we shall not pursue that here The question is: how does the polarised dielectric modify the original external field inside it
1
2008-2011
37) where ce is a constant characteristic of the dielectric and is known as the electric susceptibility of the dielectric medium It is possible to relate ce to the molecular properties of the substance, but we shall not pursue that here The question is: how does the polarised dielectric modify the original external field inside it Let us consider, for simplicity, a rectangular dielectric slab placed in a uniform external field E0 parallel to two of its faces
1
2009-2012
It is possible to relate ce to the molecular properties of the substance, but we shall not pursue that here The question is: how does the polarised dielectric modify the original external field inside it Let us consider, for simplicity, a rectangular dielectric slab placed in a uniform external field E0 parallel to two of its faces The field causes a uniform polarisation P of the dielectric
1
2010-2013
The question is: how does the polarised dielectric modify the original external field inside it Let us consider, for simplicity, a rectangular dielectric slab placed in a uniform external field E0 parallel to two of its faces The field causes a uniform polarisation P of the dielectric Thus FIGURE 2
1
2011-2014
Let us consider, for simplicity, a rectangular dielectric slab placed in a uniform external field E0 parallel to two of its faces The field causes a uniform polarisation P of the dielectric Thus FIGURE 2 22 A dielectric develops a net dipole moment in an external electric field
1
2012-2015
The field causes a uniform polarisation P of the dielectric Thus FIGURE 2 22 A dielectric develops a net dipole moment in an external electric field (a) Non-polar molecules, (b) Polar molecules
1
2013-2016
Thus FIGURE 2 22 A dielectric develops a net dipole moment in an external electric field (a) Non-polar molecules, (b) Polar molecules Rationalised 2023-24 Electrostatic Potential and Capacitance 67 every volume element Dv of the slab has a dipole moment P Dv in the direction of the field
1
2014-2017
22 A dielectric develops a net dipole moment in an external electric field (a) Non-polar molecules, (b) Polar molecules Rationalised 2023-24 Electrostatic Potential and Capacitance 67 every volume element Dv of the slab has a dipole moment P Dv in the direction of the field The volume element Dv is macroscopically small but contains a very large number of molecular dipoles
1
2015-2018
(a) Non-polar molecules, (b) Polar molecules Rationalised 2023-24 Electrostatic Potential and Capacitance 67 every volume element Dv of the slab has a dipole moment P Dv in the direction of the field The volume element Dv is macroscopically small but contains a very large number of molecular dipoles Anywhere inside the dielectric, the volume element Dv has no net charge (though it has net dipole moment)
1
2016-2019
Rationalised 2023-24 Electrostatic Potential and Capacitance 67 every volume element Dv of the slab has a dipole moment P Dv in the direction of the field The volume element Dv is macroscopically small but contains a very large number of molecular dipoles Anywhere inside the dielectric, the volume element Dv has no net charge (though it has net dipole moment) This is, because, the positive charge of one dipole sits close to the negative charge of the adjacent dipole
1
2017-2020
The volume element Dv is macroscopically small but contains a very large number of molecular dipoles Anywhere inside the dielectric, the volume element Dv has no net charge (though it has net dipole moment) This is, because, the positive charge of one dipole sits close to the negative charge of the adjacent dipole However, at the surfaces of the dielectric normal to the electric field, there is evidently a net charge density
1
2018-2021
Anywhere inside the dielectric, the volume element Dv has no net charge (though it has net dipole moment) This is, because, the positive charge of one dipole sits close to the negative charge of the adjacent dipole However, at the surfaces of the dielectric normal to the electric field, there is evidently a net charge density As seen in Fig 2
1
2019-2022
This is, because, the positive charge of one dipole sits close to the negative charge of the adjacent dipole However, at the surfaces of the dielectric normal to the electric field, there is evidently a net charge density As seen in Fig 2 23, the positive ends of the dipoles remain unneutralised at the right surface and the negative ends at the left surface
1
2020-2023
However, at the surfaces of the dielectric normal to the electric field, there is evidently a net charge density As seen in Fig 2 23, the positive ends of the dipoles remain unneutralised at the right surface and the negative ends at the left surface The unbalanced charges are the induced charges due to the external field
1
2021-2024
As seen in Fig 2 23, the positive ends of the dipoles remain unneutralised at the right surface and the negative ends at the left surface The unbalanced charges are the induced charges due to the external field Thus, the polarised dielectric is equivalent to two charged surfaces with induced surface charge densities, say sp and –sp
1
2022-2025
23, the positive ends of the dipoles remain unneutralised at the right surface and the negative ends at the left surface The unbalanced charges are the induced charges due to the external field Thus, the polarised dielectric is equivalent to two charged surfaces with induced surface charge densities, say sp and –sp Clearly, the field produced by these surface charges opposes the external field
1
2023-2026
The unbalanced charges are the induced charges due to the external field Thus, the polarised dielectric is equivalent to two charged surfaces with induced surface charge densities, say sp and –sp Clearly, the field produced by these surface charges opposes the external field The total field in the dielectric is, thereby, reduced from the case when no dielectric is present
1
2024-2027
Thus, the polarised dielectric is equivalent to two charged surfaces with induced surface charge densities, say sp and –sp Clearly, the field produced by these surface charges opposes the external field The total field in the dielectric is, thereby, reduced from the case when no dielectric is present We should note that the surface charge density ±sp arises from bound (not free charges) in the dielectric
1
2025-2028
Clearly, the field produced by these surface charges opposes the external field The total field in the dielectric is, thereby, reduced from the case when no dielectric is present We should note that the surface charge density ±sp arises from bound (not free charges) in the dielectric 2
1
2026-2029
The total field in the dielectric is, thereby, reduced from the case when no dielectric is present We should note that the surface charge density ±sp arises from bound (not free charges) in the dielectric 2 11 CAPACITORS AND CAPACITANCE A capacitor is a system of two conductors separated by an insulator (Fig
1
2027-2030
We should note that the surface charge density ±sp arises from bound (not free charges) in the dielectric 2 11 CAPACITORS AND CAPACITANCE A capacitor is a system of two conductors separated by an insulator (Fig 2
1
2028-2031
2 11 CAPACITORS AND CAPACITANCE A capacitor is a system of two conductors separated by an insulator (Fig 2 24)
1
2029-2032
11 CAPACITORS AND CAPACITANCE A capacitor is a system of two conductors separated by an insulator (Fig 2 24) The conductors have charges, say Q1 and Q2, and potentials V1 and V2
1
2030-2033
2 24) The conductors have charges, say Q1 and Q2, and potentials V1 and V2 Usually, in practice, the two conductors have charges Q and – Q, with potential difference V = V1 – V2 between them
1
2031-2034
24) The conductors have charges, say Q1 and Q2, and potentials V1 and V2 Usually, in practice, the two conductors have charges Q and – Q, with potential difference V = V1 – V2 between them We shall consider only this kind of charge configuration of the capacitor
1
2032-2035
The conductors have charges, say Q1 and Q2, and potentials V1 and V2 Usually, in practice, the two conductors have charges Q and – Q, with potential difference V = V1 – V2 between them We shall consider only this kind of charge configuration of the capacitor (Even a single conductor can be used as a capacitor by assuming the other at infinity
1
2033-2036
Usually, in practice, the two conductors have charges Q and – Q, with potential difference V = V1 – V2 between them We shall consider only this kind of charge configuration of the capacitor (Even a single conductor can be used as a capacitor by assuming the other at infinity ) The conductors may be so charged by connecting them to the two terminals of a battery
1
2034-2037
We shall consider only this kind of charge configuration of the capacitor (Even a single conductor can be used as a capacitor by assuming the other at infinity ) The conductors may be so charged by connecting them to the two terminals of a battery Q is called the charge of the capacitor, though this, in fact, is the charge on one of the conductors – the total charge of the capacitor is zero
1
2035-2038
(Even a single conductor can be used as a capacitor by assuming the other at infinity ) The conductors may be so charged by connecting them to the two terminals of a battery Q is called the charge of the capacitor, though this, in fact, is the charge on one of the conductors – the total charge of the capacitor is zero The electric field in the region between the conductors is proportional to the charge Q
1
2036-2039
) The conductors may be so charged by connecting them to the two terminals of a battery Q is called the charge of the capacitor, though this, in fact, is the charge on one of the conductors – the total charge of the capacitor is zero The electric field in the region between the conductors is proportional to the charge Q That is, if the charge on the capacitor is, say doubled, the electric field will also be doubled at every point
1
2037-2040
Q is called the charge of the capacitor, though this, in fact, is the charge on one of the conductors – the total charge of the capacitor is zero The electric field in the region between the conductors is proportional to the charge Q That is, if the charge on the capacitor is, say doubled, the electric field will also be doubled at every point (This follows from the direct proportionality between field and charge implied by Coulomb’s law and the superposition principle
1
2038-2041
The electric field in the region between the conductors is proportional to the charge Q That is, if the charge on the capacitor is, say doubled, the electric field will also be doubled at every point (This follows from the direct proportionality between field and charge implied by Coulomb’s law and the superposition principle ) Now, potential difference V is the work done per unit positive charge in taking a small test charge from the conductor 2 to 1 against the field
1
2039-2042
That is, if the charge on the capacitor is, say doubled, the electric field will also be doubled at every point (This follows from the direct proportionality between field and charge implied by Coulomb’s law and the superposition principle ) Now, potential difference V is the work done per unit positive charge in taking a small test charge from the conductor 2 to 1 against the field Consequently, V is also proportional to Q, and the ratio Q/V is a constant: Q C =V (2
1
2040-2043
(This follows from the direct proportionality between field and charge implied by Coulomb’s law and the superposition principle ) Now, potential difference V is the work done per unit positive charge in taking a small test charge from the conductor 2 to 1 against the field Consequently, V is also proportional to Q, and the ratio Q/V is a constant: Q C =V (2 38) The constant C is called the capacitance of the capacitor
1
2041-2044
) Now, potential difference V is the work done per unit positive charge in taking a small test charge from the conductor 2 to 1 against the field Consequently, V is also proportional to Q, and the ratio Q/V is a constant: Q C =V (2 38) The constant C is called the capacitance of the capacitor C is independent of Q or V, as stated above
1
2042-2045
Consequently, V is also proportional to Q, and the ratio Q/V is a constant: Q C =V (2 38) The constant C is called the capacitance of the capacitor C is independent of Q or V, as stated above The capacitance C depends only on the FIGURE 2
1
2043-2046
38) The constant C is called the capacitance of the capacitor C is independent of Q or V, as stated above The capacitance C depends only on the FIGURE 2 23 A uniformly polarised dielectric amounts to induced surface charge density, but no volume charge density
1
2044-2047
C is independent of Q or V, as stated above The capacitance C depends only on the FIGURE 2 23 A uniformly polarised dielectric amounts to induced surface charge density, but no volume charge density FIGURE 2
1
2045-2048
The capacitance C depends only on the FIGURE 2 23 A uniformly polarised dielectric amounts to induced surface charge density, but no volume charge density FIGURE 2 24 A system of two conductors separated by an insulator forms a capacitor
1
2046-2049
23 A uniformly polarised dielectric amounts to induced surface charge density, but no volume charge density FIGURE 2 24 A system of two conductors separated by an insulator forms a capacitor Rationalised 2023-24 Physics 68 geometrical configuration (shape, size, separation) of the system of two conductors
1
2047-2050
FIGURE 2 24 A system of two conductors separated by an insulator forms a capacitor Rationalised 2023-24 Physics 68 geometrical configuration (shape, size, separation) of the system of two conductors [As we shall see later, it also depends on the nature of the insulator (dielectric) separating the two conductors
1
2048-2051
24 A system of two conductors separated by an insulator forms a capacitor Rationalised 2023-24 Physics 68 geometrical configuration (shape, size, separation) of the system of two conductors [As we shall see later, it also depends on the nature of the insulator (dielectric) separating the two conductors ] The SI unit of capacitance is 1 farad (=1 coulomb volt-1) or 1 F = 1 C V–1
1
2049-2052
Rationalised 2023-24 Physics 68 geometrical configuration (shape, size, separation) of the system of two conductors [As we shall see later, it also depends on the nature of the insulator (dielectric) separating the two conductors ] The SI unit of capacitance is 1 farad (=1 coulomb volt-1) or 1 F = 1 C V–1 A capacitor with fixed capacitance is symbolically shown as ---||---, while the one with variable capacitance is shown as
1
2050-2053
[As we shall see later, it also depends on the nature of the insulator (dielectric) separating the two conductors ] The SI unit of capacitance is 1 farad (=1 coulomb volt-1) or 1 F = 1 C V–1 A capacitor with fixed capacitance is symbolically shown as ---||---, while the one with variable capacitance is shown as Equation (2
1
2051-2054
] The SI unit of capacitance is 1 farad (=1 coulomb volt-1) or 1 F = 1 C V–1 A capacitor with fixed capacitance is symbolically shown as ---||---, while the one with variable capacitance is shown as Equation (2 38) shows that for large C, V is small for a given Q
1
2052-2055
A capacitor with fixed capacitance is symbolically shown as ---||---, while the one with variable capacitance is shown as Equation (2 38) shows that for large C, V is small for a given Q This means a capacitor with large capacitance can hold large amount of charge Q at a relatively small V
1
2053-2056
Equation (2 38) shows that for large C, V is small for a given Q This means a capacitor with large capacitance can hold large amount of charge Q at a relatively small V This is of practical importance
1
2054-2057
38) shows that for large C, V is small for a given Q This means a capacitor with large capacitance can hold large amount of charge Q at a relatively small V This is of practical importance High potential difference implies strong electric field around the conductors
1
2055-2058
This means a capacitor with large capacitance can hold large amount of charge Q at a relatively small V This is of practical importance High potential difference implies strong electric field around the conductors A strong electric field can ionise the surrounding air and accelerate the charges so produced to the oppositely charged plates, thereby neutralising the charge on the capacitor plates, at least partly
1
2056-2059
This is of practical importance High potential difference implies strong electric field around the conductors A strong electric field can ionise the surrounding air and accelerate the charges so produced to the oppositely charged plates, thereby neutralising the charge on the capacitor plates, at least partly In other words, the charge of the capacitor leaks away due to the reduction in insulating power of the intervening medium
1
2057-2060
High potential difference implies strong electric field around the conductors A strong electric field can ionise the surrounding air and accelerate the charges so produced to the oppositely charged plates, thereby neutralising the charge on the capacitor plates, at least partly In other words, the charge of the capacitor leaks away due to the reduction in insulating power of the intervening medium The maximum electric field that a dielectric medium can withstand without break-down (of its insulating property) is called its dielectric strength; for air it is about 3 × 106 Vm–1
1
2058-2061
A strong electric field can ionise the surrounding air and accelerate the charges so produced to the oppositely charged plates, thereby neutralising the charge on the capacitor plates, at least partly In other words, the charge of the capacitor leaks away due to the reduction in insulating power of the intervening medium The maximum electric field that a dielectric medium can withstand without break-down (of its insulating property) is called its dielectric strength; for air it is about 3 × 106 Vm–1 For a separation between conductors of the order of 1 cm or so, this field corresponds to a potential difference of 3 × 104 V between the conductors
1
2059-2062
In other words, the charge of the capacitor leaks away due to the reduction in insulating power of the intervening medium The maximum electric field that a dielectric medium can withstand without break-down (of its insulating property) is called its dielectric strength; for air it is about 3 × 106 Vm–1 For a separation between conductors of the order of 1 cm or so, this field corresponds to a potential difference of 3 × 104 V between the conductors Thus, for a capacitor to store a large amount of charge without leaking, its capacitance should be high enough so that the potential difference and hence the electric field do not exceed the break-down limits
1
2060-2063
The maximum electric field that a dielectric medium can withstand without break-down (of its insulating property) is called its dielectric strength; for air it is about 3 × 106 Vm–1 For a separation between conductors of the order of 1 cm or so, this field corresponds to a potential difference of 3 × 104 V between the conductors Thus, for a capacitor to store a large amount of charge without leaking, its capacitance should be high enough so that the potential difference and hence the electric field do not exceed the break-down limits Put differently, there is a limit to the amount of charge that can be stored on a given capacitor without significant leaking
1
2061-2064
For a separation between conductors of the order of 1 cm or so, this field corresponds to a potential difference of 3 × 104 V between the conductors Thus, for a capacitor to store a large amount of charge without leaking, its capacitance should be high enough so that the potential difference and hence the electric field do not exceed the break-down limits Put differently, there is a limit to the amount of charge that can be stored on a given capacitor without significant leaking In practice, a farad is a very big unit; the most common units are its sub-multiples 1 mF = 10–6 F, 1 nF = 10–9 F, 1 pF = 10–12 F, etc
1
2062-2065
Thus, for a capacitor to store a large amount of charge without leaking, its capacitance should be high enough so that the potential difference and hence the electric field do not exceed the break-down limits Put differently, there is a limit to the amount of charge that can be stored on a given capacitor without significant leaking In practice, a farad is a very big unit; the most common units are its sub-multiples 1 mF = 10–6 F, 1 nF = 10–9 F, 1 pF = 10–12 F, etc Besides its use in storing charge, a capacitor is a key element of most ac circuits with important functions, as described in Chapter 7
1
2063-2066
Put differently, there is a limit to the amount of charge that can be stored on a given capacitor without significant leaking In practice, a farad is a very big unit; the most common units are its sub-multiples 1 mF = 10–6 F, 1 nF = 10–9 F, 1 pF = 10–12 F, etc Besides its use in storing charge, a capacitor is a key element of most ac circuits with important functions, as described in Chapter 7 2
1
2064-2067
In practice, a farad is a very big unit; the most common units are its sub-multiples 1 mF = 10–6 F, 1 nF = 10–9 F, 1 pF = 10–12 F, etc Besides its use in storing charge, a capacitor is a key element of most ac circuits with important functions, as described in Chapter 7 2 12 THE PARALLEL PLATE CAPACITOR A parallel plate capacitor consists of two large plane parallel conducting plates separated by a small distance (Fig
1
2065-2068
Besides its use in storing charge, a capacitor is a key element of most ac circuits with important functions, as described in Chapter 7 2 12 THE PARALLEL PLATE CAPACITOR A parallel plate capacitor consists of two large plane parallel conducting plates separated by a small distance (Fig 2
1
2066-2069
2 12 THE PARALLEL PLATE CAPACITOR A parallel plate capacitor consists of two large plane parallel conducting plates separated by a small distance (Fig 2 25)
1
2067-2070
12 THE PARALLEL PLATE CAPACITOR A parallel plate capacitor consists of two large plane parallel conducting plates separated by a small distance (Fig 2 25) We first take the intervening medium between the plates to be vacuum
1
2068-2071
2 25) We first take the intervening medium between the plates to be vacuum The effect of a dielectric medium between the plates is discussed in the next section
1
2069-2072
25) We first take the intervening medium between the plates to be vacuum The effect of a dielectric medium between the plates is discussed in the next section Let A be the area of each plate and d the separation between them
1
2070-2073
We first take the intervening medium between the plates to be vacuum The effect of a dielectric medium between the plates is discussed in the next section Let A be the area of each plate and d the separation between them The two plates have charges Q and –Q
1
2071-2074
The effect of a dielectric medium between the plates is discussed in the next section Let A be the area of each plate and d the separation between them The two plates have charges Q and –Q Since d is much smaller than the linear dimension of the plates (d2 << A), we can use the result on electric field by an infinite plane sheet of uniform surface charge density (Section 1
1
2072-2075
Let A be the area of each plate and d the separation between them The two plates have charges Q and –Q Since d is much smaller than the linear dimension of the plates (d2 << A), we can use the result on electric field by an infinite plane sheet of uniform surface charge density (Section 1 15)
1
2073-2076
The two plates have charges Q and –Q Since d is much smaller than the linear dimension of the plates (d2 << A), we can use the result on electric field by an infinite plane sheet of uniform surface charge density (Section 1 15) Plate 1 has surface charge density s = Q/A and plate 2 has a surface charge density –s
1
2074-2077
Since d is much smaller than the linear dimension of the plates (d2 << A), we can use the result on electric field by an infinite plane sheet of uniform surface charge density (Section 1 15) Plate 1 has surface charge density s = Q/A and plate 2 has a surface charge density –s Using Eq
1
2075-2078
15) Plate 1 has surface charge density s = Q/A and plate 2 has a surface charge density –s Using Eq (1
1
2076-2079
Plate 1 has surface charge density s = Q/A and plate 2 has a surface charge density –s Using Eq (1 33), the electric field in different regions is: Outer region I (region above the plate 1), 0 0 0 2 2 E σ σ ε ε = − = (2
1
2077-2080
Using Eq (1 33), the electric field in different regions is: Outer region I (region above the plate 1), 0 0 0 2 2 E σ σ ε ε = − = (2 39) FIGURE 2
1
2078-2081
(1 33), the electric field in different regions is: Outer region I (region above the plate 1), 0 0 0 2 2 E σ σ ε ε = − = (2 39) FIGURE 2 25 The parallel plate capacitor
1
2079-2082
33), the electric field in different regions is: Outer region I (region above the plate 1), 0 0 0 2 2 E σ σ ε ε = − = (2 39) FIGURE 2 25 The parallel plate capacitor Rationalised 2023-24 Electrostatic Potential and Capacitance 69 Outer region II (region below the plate 2), 0 0 0 2 2 E σ σ ε ε = − = (2
1
2080-2083
39) FIGURE 2 25 The parallel plate capacitor Rationalised 2023-24 Electrostatic Potential and Capacitance 69 Outer region II (region below the plate 2), 0 0 0 2 2 E σ σ ε ε = − = (2 40) In the inner region between the plates 1 and 2, the electric fields due to the two charged plates add up, giving 0 0 0 0 2 2 Q E A σ σ σ ε ε ε ε = + = = (2
1
2081-2084
25 The parallel plate capacitor Rationalised 2023-24 Electrostatic Potential and Capacitance 69 Outer region II (region below the plate 2), 0 0 0 2 2 E σ σ ε ε = − = (2 40) In the inner region between the plates 1 and 2, the electric fields due to the two charged plates add up, giving 0 0 0 0 2 2 Q E A σ σ σ ε ε ε ε = + = = (2 41) The direction of electric field is from the positive to the negative plate
1
2082-2085
Rationalised 2023-24 Electrostatic Potential and Capacitance 69 Outer region II (region below the plate 2), 0 0 0 2 2 E σ σ ε ε = − = (2 40) In the inner region between the plates 1 and 2, the electric fields due to the two charged plates add up, giving 0 0 0 0 2 2 Q E A σ σ σ ε ε ε ε = + = = (2 41) The direction of electric field is from the positive to the negative plate Thus, the electric field is localised between the two plates and is uniform throughout
1
2083-2086
40) In the inner region between the plates 1 and 2, the electric fields due to the two charged plates add up, giving 0 0 0 0 2 2 Q E A σ σ σ ε ε ε ε = + = = (2 41) The direction of electric field is from the positive to the negative plate Thus, the electric field is localised between the two plates and is uniform throughout For plates with finite area, this will not be true near the outer boundaries of the plates
1
2084-2087
41) The direction of electric field is from the positive to the negative plate Thus, the electric field is localised between the two plates and is uniform throughout For plates with finite area, this will not be true near the outer boundaries of the plates The field lines bend outward at the edges — an effect called ‘fringing of the field’
1
2085-2088
Thus, the electric field is localised between the two plates and is uniform throughout For plates with finite area, this will not be true near the outer boundaries of the plates The field lines bend outward at the edges — an effect called ‘fringing of the field’ By the same token, s will not be strictly uniform on the entire plate
1
2086-2089
For plates with finite area, this will not be true near the outer boundaries of the plates The field lines bend outward at the edges — an effect called ‘fringing of the field’ By the same token, s will not be strictly uniform on the entire plate [E and s are related by Eq
1
2087-2090
The field lines bend outward at the edges — an effect called ‘fringing of the field’ By the same token, s will not be strictly uniform on the entire plate [E and s are related by Eq (2
1
2088-2091
By the same token, s will not be strictly uniform on the entire plate [E and s are related by Eq (2 35)
1
2089-2092
[E and s are related by Eq (2 35) ] However, for d2 << A, these effects can be ignored in the regions sufficiently far from the edges, and the field there is given by Eq