16) Two charged spheres of radii 10 cm and 15 cm are connected by a thin wire. No current will flow if they have

  1. the same charge
  2. the same energy
  3. the same field on their surface
  4. the same potential
ANSWER
Answer: ( 4 )
EXPLANATION
No answer description required for this question.

17) The relative permittivity of most materials lies between

  1. 20 and 100
  2. 10 and 20
  3. 100 and 200
  4. 1 and 10
ANSWER
Answer: ( 4 )
EXPLANATION
No answer description required for this question.

18) If the relative permittivity of the medium increases, the electric intensity at a point due to a given charge

  1. decreases
  2. increases
  3. remains the same
  4. none of the above
ANSWER
Answer: ( 1 )
EXPLANATION
Electric intensity at a point in a medium due to charge Q is:

E= 9×109 × (Q)/(εrd2)

Therefore, as the relative permittivity of the medium increases, the electric field intensity decreases.

19) An electric field can deflect

  1. x-rays
  2. neutrons
  3. α-particles
  4. γ-rays
ANSWER
Answer: ( 3 )
EXPLANATION
No answer description required for this question.




20) Electric lines of force enter or leave a charged surface at an angle of

  1. 90°
  2. 30°
  3. 60°
  4. depends upon surface condition
ANSWER
Answer: ( 1 )
EXPLANATION
No answer description required for this question.

21) One thousand electrons, each of which carries a charge of -1.6×10-12 coulomb are removed from an initially neutral pitch ball. The resulting charge on the pitch ball is

  1. 1.6×10-15 coulomb
  2. 1.6×10-23 coulomb
  3. -1.6×10-15 coulomb
  4. -1.6×10-23 coulomb
ANSWER
Answer: ( 1 )
EXPLANATION
No answer description required for this question.

22) When the potential difference across the electric field intensity between the parallel plate air capacitor is doubled, plates

  1. is not change
  2. is halved
  3. is doubled
  4. is independent of the potential difference
ANSWER
Answer: ( 4 )
EXPLANATION
No answer description required for this question.

23) Midway between two equal and similar charges, a third equal and similar charge is placed, then this third charge will

  1. remain in stable equilibrium
  2. be in unstable equilibrium
  3. not be in equilibrium
  4. will move out of the field of influence of the two charges
ANSWER
Answer: ( 1 )
EXPLANATION
No answer description required for this question.




24) One volt is the same as

  1. one joule
  2. one coulomb
  3. one joule/coulomb
  4. one coulomb/joule
ANSWER
Answer: ( 3 )
EXPLANATION
As,  V=J/C.

25) One farad is the same as

  1. one coulomb/volt
  2. one joule/volt
  3. one joule/coulomb
  4. one coulomb/joule
ANSWER
Answer: ( 1 )
EXPLANATION
As,  the farad is coulomb/volt.

26) When a dielectric is placed in an electric field, the field strength

  1. increases
  2. decreases
  3. remains unchanged
  4. reduces to zero
ANSWER
Answer: ( 2 )
EXPLANATION
No answer description required for this question.

27) Electric potential is a

  1. scalar quantity
  2. vector quantity
  3. dimensionless quantity
  4. none of the above
ANSWER
Answer: ( 1 )
EXPLANATION
No answer description required for this question.




28) The potential at a point due to a charge is 9 V. If the distance is increased three times, the potential at that point will be

  1. 27 V
  2. 3 V
  3. 12 V
  4. 18 V
ANSWER
Answer: ( 1 )
EXPLANATION
Electric potential at a point due to charge Q is:

V= 9×109 (Q/εrd)

29) A hollow metal sphere of radius 5 cm is charged such that potential on its surface is 10 V. The potential at the center of the sphere is

  1. 10 V
  2. 0 V
  3. same as at point 5 cm away from the surface
  4. same as at point 25 cm away from the surface
ANSWER
Answer: ( 1 )
EXPLANATION
No answer description required for this question.

30) If a unit charge is taken from one point to another over an equipotential surface, then

  1. work is done on the charge
  2. work is done by the charge
  3. work on the charge is constant
  4. no work is done
ANSWER
Answer: ( 4 )
EXPLANATION
No answer description required for this question.

Pin It on Pinterest