Coulomb's Law
1. Two charges are placed at a certain distance apart. A brass sheet is placed between them.
The force between them will
a) increase
b) decrease
c) remains unchanged
d) none of the above
2. When the relative permittivity of the medium is increased, the force between two charges
placed at a given distance apart
a) increases
b) decreases
c) remains the same
d) none of the above
3. As one penetrates a uniformly charged sphere, the electric flied strength E
a) increases
b) decreases
c) is zero at all points
d) remains same as at surface
4. A point charge in space is attracted towards a dielectric material because of the
a) phenomenon of dielectric polarization
b) maximization of electrostatics flux
c) dielectric hysteresis
d) none of the above
5. A region around a stationary electric charge has
a) magnetic field
b) electric field
c) both electric and magnetic field
d) neither electric nor magnetic field
6. A charged oil drop is stationary between a pair of horizontal parallel plates. If the drop
carries a charge 3.2×10-10 coulomb and has a mass 1.6×10-19 kg, then the potential
difference between the plates is
a) 50 V
b) 80 V
c) 100 V
d) cannot be calculated on the basis of given data
7. The force of attraction or repulsion between two charges q1 and q2 at a distance d meters
apart is proportional to the product of charges q1 and q2 and is inversely proportional to the
distance square between the two charges. Above statement is attributed as:
a) Lenz’s law
b) Faraday law
c) Coulomb’s law
d) Maxwell’s law
8. A positive and a negative charge are initially 4 cm apart. When they are moved closer
together so that they are now only 1 cm apart, the force between them will be
a) 16 times larger than before
b) 8 times larger than before
c) 4 times larger than before
d) 4 times smaller than before
9. Two charged spheres of radii 10 cm and 15 cm are connected by a thin wire. No current
will flow if they have
a) the same charge
b) the same energy
c) the same field on their surface
d) the same potential
10. The relative permittivity of most materials lies between
a) 20 and 100
b) 10 and 20
c) 100 and 200
d) 1 and 10
11. If the relative permittivity of the medium increases, the electric intensity at a point due to
a given charge
a) decreases
b) increases
c) remains the same
d) none of the above
12. An electric field can deflect
a) x-rays
b) neutrons
c) α-particles
d) γ-rays
13. 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
a) 1.6×10-15 coulomb
b) 1.6×10-23 coulomb
c) -1.6×10-15 coulomb
d) -1.6×10-23 coulomb
14. When the potential difference across the electric field intensity between the parallel plate
air capacitor is doubled, plates
a) is not change
b) is halved
c) is doubled
d) is independent of the potential difference
15. Midway between two equal and similar charges, a third equal and similar charge is
placed, then this third charge will
a) remain in stable equilibrium
b) be in unstable equilibrium
c) not be in equilibrium
d) will move out of the field of influence of the two charges
16. One volt is the same as
a) one joule
b) one coulomb
c) one joule/coulomb
d) one coulomb/joule
17. One farad is the same as
a) one coulomb/volt
b) one joule/volt
c) one joule/coulomb
d) one coulomb/joule
18. When a dielectric is placed in an electric field, the field strength
a) increases
b) decreases
c) remains unchanged
d) reduces to zero
19. Electric potential is a
a) scalar quantity
b) vector quantity
c) dimensionless quantity
d) none of the above
20. 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
a) 27 V
b) 3V
c) 12 V
d) 18 V
