Q.1
Electric potential is given by V=6x - 8xy2-8y+6yz-4z2 then electric force acting on 2C point charge placed on the origin will be [ Raj.PET 1997]
  • a)2N
  • b) 6N
  • c)8N
  • d)20N
Q.2
The ratio of momentum of an electron and an alpha particle which are accelerated from rest by a potential difference of 100V is [ MNR 1994]
  • a) 1
    ch-13_qn-54choice_img_no2.png
  • b)
    ch-13_qn-54choice_img_no3.png
  • c)
    ch-13_qn-54choice_img_no4.png
  • d)
Q.3
A region surrounding a stationary electric dipole has [ MPPMT 1994]
  • a) Magnetic field only
  • b) Electric field only
  • c)Both electric and magnetic fields
  • d)No electric and magnetic fields
Q.4
An electron is moving around infinite linear positive charge in the orbit of 0.1m. If the linear change density is 1µC/m, the velocity of electron will be [ RajPET 1996]
  • a) 0.562×107 m/sec
  • b) 5.62×107 m/sec
  • c) 5.2×105 m/sec
  • d) 0.0562×107 m/sec
Q.5
The dielectric constant K of an insulator can not be [ JIPMER 1998]
  • a)4
  • b) 6
  • c)∞
  • d)9
Q.6
A solid metallic sphere has a charge +3Q concentric with this sphere is a conducting spherical shell having charge -Q. The radius of a sphere is 'a' and that of the spherical shell is 'b'. (b > a). What is the electric field at a distance R ( a < R< b) from the centre? [ PMT 1995]
  • a)
    ch-13_qn-58choice_img_no1.png
  • b)
    ch-13_qn-58choice_img_no2.png
  • c)
    ch-13_qn-58choice_img_no3.png
  • d)
    ch-13_qn-58choice_img_no4.png
Q.7
A flat circular disc has a charge +Q uniformly distributed on the disc. A charge +Q is thrown with kinetic energy E, towards the disc along its normal axis. The charge Q will [ PMT 1995]
  • a) hit the disc at the centre
  • b) return back along its path after touching the disc
  • c)return back along its path, without touching the disc
  • d)any of the above three situations is possible, depending on the magnitude of E
Q.8
An electric dipole is placed along x-axis at the origin O. A point P is situated at a distance 20 cm from this origin such that OP makes an angle π/3 with the X-axis. If the electric filed at P makes an angle θ with the X-axis the value of θ would be [ MPPMT 1997]
  • a) π/3
  • b) π/3 + tan⁻¹(√3 / 2)
  • c) 2π/3
  • d) tan⁻¹(√3 / 2)
Q.9
A charge q is placed at the centre of a cube of side a. The electric flux passing through any one face of the cube is [ CPMT 1993]
  • a)q/ εo
  • b) q/ (3εo)
  • c)q/ (6εo)
  • d)6q/εo
Q.10
Three charges +Q each are placed at the corners A,B and C of an equilateral triangle. At the circum centre O, the electric fieldstrenght is ; ( r be the distance between corners and circumcentre) [ CPMT 1998] k=1 /4πεo
  • a) zero
  • d)kQ2/ r2
  • b) 3kQ/ r²
  • c)kQ/ r²
Q.11
There are 27 drops of a conducting fluid. Each has a radius a and they are charged to potential Vo. These are combined to form a bigger drop. Its potential will be [ MPPMT 1994]
  • a) Vo
  • b) 3Vo
  • c) 9Vo
  • d) 27Vo
Q.12
Two identical thin rings, each of radius R m are co-axially placed at distance R metre apart. If Q1 and Q2 C are respectively the charges uniformly spread on the two rings, the work done in moving a charge q from the centre of one ring to that of the other is [ MPMT 1999]
  • a)Zero
    ch-13_qn-65choice_img_no2.png
  • b)
    ch-13_qn-65choice_img_no3.png
  • c)
    ch-13_qn-65choice_img_no4.png
  • d)
Q.13
A sphere of radius R has a uniform distribution of electric charge in its volume. At a distance x from its centre, for x
  • b) 1/x
  • c)x
  • d)x2
  • a) 1/x²
Q.14
Charges of +(10/3)×10-9 C are placed at each of the four corners of a square of side 8cm. The potential at the intersection of diagonals is [ BIT 1993]
  • a) 150√2 V
  • b) 1500√2 V
  • c)900√2 V
  • d)900 V
Q.15
Equal charges q are placed at the four corners A,B,C and D of a square of length a. The magnitude of the force on the charge at D will be [ MPPMT 1994]
  • a)
    ch-13_qn-68choice_img_no1.png
  • b)
    ch-13_qn-68choice_img_no2.png
  • c)
    ch-13_qn-68choice_img_no3.png
  • d)
    ch-13_qn-68choice_img_no4.png
Q.16
Electric charges q, q and -2q are placed at the corners of an equilateral triangle ABD of side l. The magnitude of electric dipole moment of the system is : [ MPPMT 1994]
  • a)ql
  • b) 2ql
  • c)√3 (ql)
  • d)4ql
Q.17
A charged conductor B is kept inside another hollow conductor A. B is in contact with A. What will be effect of charge on B
  • a) Total charge on B is transferred to A and comes out on the outer surface of A
  • b) Total charge on B is transferred to A and remains on the inner surface of A
  • c)Opposite charge is induced on the outer surface of A.
  • d)Charge on B is not transferred to A t all
Q.18
The following figure shows two parallel equipotential surfaces A and B kept at a small distance r from each other. A point charge of -q coul is taken from the surface A to B. The amount of net work W done will be given by : [ CPMT 1988] k=1/ 4πεo
ch-13_que_no-72_img_no1.png
  • a) -kq/r
  • d) zero
  • b) kq/r²
  • c) -kq/r²
Q.19
When a charge of 3 C is placed in a uniform electric field, it experiences a force of 3000N, with this field, potential difference between two pints separated by distance of 1 cm is [ MP 1986]
  • a)10 V
  • b) 90 V
  • c)1000 V
  • d)3000 V
Q.20
Three charges 2Q, -q- and -q are located at the vertices of an equilateral triangle. At the circumcentre of the triangle [ MPPMT 1986]
  • a) the field is zero but potential is not zero
  • b) the field is non zero but potential is zero
  • c)both field and potential are zero
  • d)both, field and potential are non zero
Q.21
There is a solid sphere of radius R of metal having uniform distributed charge. What is the relation between electric field 'E' and distance 'r' from the centre ( r < R) [ BHU 1998]
  • a)E ∝ r-2
  • b) E ∝ r-1
  • c)E ∝ r
  • d)E ∝ r2
Q.22
A sphere of 4cm radius is suspended within a hollow sphere of 6 cm radius. the inner sphere is charged to a potential of 3 e.s.u. When the outer sphere is earthed, the charge on the inner sphere is [ JIPMER 1998]
  • a) 54 esu
  • b) 1/4 e.s.u
  • c) 30 e.s.u
  • d) 36 e.s.u
Q.23
There is an electric field E in x-direction. If the work done on moving charge 0.2C through a distance of 2 meters along a line making an angle 60° with x-axis is 4.0, what is the value of E? [ CBSE 1995]
  • a)√3 N/C
  • b) 4 N/C
  • c)5 N/C
  • d)none of these
Q.24
Two equal charges q are placed at a distance of 2a, and a third charge -2q is placed at the mid-point. The potential energy of the system is [ MPPMT 1997]
  • a) q2 / 8πεoa
  • b) 6q2 / 8πεoa
  • c)- 7q2 / 8πεoa
  • d)9q2 / 8πεoa
Q.25
A soap bubble is given a negative charge then its radius{MNR 198]
  • a) decreases
  • b) increases
  • c)remains unchanged
  • d)nothing can be predicted as information is insufficient
Q.26
A hollow charged metal sphere has radius r. If the potential difference between its surface and a point at distance 3r from the centre is V, then the electric field intensity at a distance 3r from the centre is [ MPPMT 1985]
  • a) V/6r
  • b) V/4r
  • c) V/3r
  • d) V/2r
Q.27
Four charges are placed on corners of a square as shown in figure having sides 5cm. If q is one micro coulomb then the electric field intensity at centre will be [ Raj. PET 1997]
ch-13_que_no-81_img_no1.png
  • a)1.02 ×107 N/C upward
  • b) 2.04 ×107 N/C downwards
  • c)2.04 ×107 N/C upward
  • d)1.02 ×107 N/C downwards
Q.28
In an electric gun, the electrons are accelerated through a p.D. of V volts. Taking electronic charge and mass to be e and m respectively, the maximum velocity attained by them is [ BHU 1995]
  • a) 2eV/m
  • b) √(2eV/m)
  • c)(2m/eV)
  • d)(V2/2em)
Q.29
A small sphere of radius r is kept inside a hollow sphere of radius R ( R < r) concentrically. The large sphere are charged by charges Q and q respectively. Both the spheres are separated from each other. The potential difference depend on [ Raj. PET 1996]
  • a) only on charge q
  • b) only on charge Q
  • c)both on charge q and Q
  • d)does not depends upon any of them
Q.30
For a given surface, the Gauss's law is stated as From this, we can conclude that [ PMT 1995]
ch-13_que_no-85_img_no1.png
  • a)E is necessarily zero on the surface
  • b) E is perpendicular to the surface at every point
  • c)the total flux through the surface is zero
  • d)the flux is only going out of the surface
Q.31
A charged water drop whose radius is 0.1µm is in equilibrium in an electric field. If charges on it is equal to charges of an electron, then intensity of electric field will be 9 g=10 m/s2)
  • a) 1.61 N/C
  • b) 26.2 N/C
  • c)262 N/C
  • d)1610 N/C
Q.32
A charge of 5C is given a displacement of 0.5m and work done in the process is 10J. The difference of potential between the two points is [ MPPET 1990]
  • a) 2 V
  • b) 1 V
  • c)0.25 V
  • d)4 V
Q.33
A particle A has charge +q and the particle B has charge +4q with each of them having the same mass m. When allowed to fall from rest through the same electrical potential difference, the ratio of their speed VA/ VB will become [ MNR 1991]
  • a) 2:1
  • b) 1:2
  • c) 1:4
  • d) 4:1
Q.34
A hollow metal sphere of radius 5cm is charged such that potential on its surface is 10V. The potential at a distance of 2cm from the centre of the sphere is [ MPPMT 1991]
  • a)zero
  • b) 10V
  • c)4V
  • d)10/3 V
Q.35
Two point charges 20 mC and 80 mC are separated by a distance 10 cm. The point at which the intensity of electric filed will be zero along the line joining two charges will be [ Raj. PET 1996]
  • a) -0.1 m
  • b) -0.04 m
  • c)0.003 m
  • d)0.033 m
Q.36
With a rise in temperature, the dielectric constant K of a liquid.. [ MPPET 1999]
  • a) increases
  • b) decreases
  • c)remains unchanged
  • d)changes erratically
Q.37
The electric potential V as a function of distance x ( in metre) is given by V=(5x2 + 10x - 9) volt. The value of electric field at x=1m would be [ MPPMT 1999]
  • d) -20 volt/m
  • a) 20 volt/m
  • b) 6 volt/m
  • c) 11 volt/m
Q.38
At a certain distance from a point charge, the electric field is 500V/m and the potential is 3000V. What is the distance? [ PMT 1995]
  • a)6 m
  • b) 12 m
  • c)36 m
  • d)144 m
Q.39
A point Q lies on the perpendicular bisector of an electrical dipole moment p. If the distance of Q from the dipole is r ( much larger than the size of dipole) then electric field at Q is proportional to [ CBSE 1998]
  • a) p-1 and r-2
  • b) p and r-2
  • c)p and r-3
  • d)p2 and r-3
Q.40
Equal charges are given to two spheres of different radii. The potential will [ MPPMT 1998]
  • a) be more on the smaller sphere
  • b) be more on the bigger sphere
  • c)be equal on the both the sphere
  • d)depend on the nature of the material of spheres
Q.41
Two point charges Q and -3Q are placed at some distance apart. If the electric field at the location of Q is E, then at the location of -3Q it is [ BIT 1987]
  • a) -E
  • b) E/3
  • c) -3E
  • d) -E/3
Q.42
A particle of mass m and charge q is placed at rest in uniform electric field E and then freed. The kinetic energy attended by the particle after moving a distance y is [ CBSE 1998]
  • a)qE2y
  • b) qEy
  • c)qEy2
  • d)qEy
Q.43
Two equal negative charges -q are fixed at points ( 0, a) and (0, -a). Positive charge Q is released from rest at a point (2a, 0) on the X-axis, the charge Q will [ CPMT 1995]
  • a) execute SHM about the origin
  • b) move to origin and remain at rest
  • c)move to infinity
  • d)execute oscillations but not S.H.M
Q.44
The electric field at distance r from a uniformly charged infinity sheet of surface charge density σ will be [ Raj.PET 1996]
  • a) σ / εo
  • b) σ / 2εo
  • c) σ2 / 2εo
  • d)σ2 / εo
Q.45
A hollow sphere of charge does not produce an electric field at any [ MNR 1985]
  • a) interior point
  • b) outer point
  • c) surface point
  • d) none of the above
Q.46
A uniform electric field having a magnitude Eo and direction along positive X-axis exists. If the electric potential V is zero at X=0, then its value at x=+x will be [ MPPMT 1987]
  • a)Vx=x Eo
  • b) Vx=-x Eo
  • c)Vx=x² Eo
  • d)Vx=-x² Eo
Q.47
The angle between the equipotential surface and the electric field ( or line of force) at any point on the equipotential surface is [ MPPMT 1995]
  • a) 0°
  • b) 45°
  • c)90°
  • d)180°
Q.48
The electric force between two point charges q1 and q2 at separation r is given by The constant K [ CPMT 1993]
ch-13_que_no-103_img_no1.png
  • a) Depends upon system of unit only
  • b) Depends upon medium between the charges
  • c)Depends on both 'a' and 'b'
  • d)Is independent of both 'a' and 'b'
Q.49
One metallic sphere A is given positive charge whereas another identical metallic sphere B of exactly same mass as of A is given equal amount of negative charge . Then [ AMU 1995]
  • a) mass of A and mass of B still remain equal
  • b) mass of A increases
  • c) mass of B decreases
  • d) mass of B increases
Q.50
The point charges -Q and +2Q are placed at a distance R apart. Where should a third point charge be placed so that it is in equilibrium [ CPMT 1993]
  • a)At a point on the right of 2Q
  • b) At a point on the left of -Q
  • c)between -Q and 2Q
  • d)at a point on a line perpendicular to the line joining -Q and 2Q
0 h : 0 m : 1 s