(a) grinding
(b) shielding
(c) grounding
(d) rubbing
2. The electric charge in uniform motion produces
(a) both electric and magnetic fields
(b) neither electric nor magnetic field
(c) a magnetic field only
(d) an electric field only
3. Which of the following is a semi-conductor?
(a) Gold
(b) Aluminum
(c) Germanium
(d) Glass
4. The unit of charge is
(a) ohm
(b) volt
(c) couloumb
(d) ampere
5. The force exerted by two charged bodies on one another obeys Coulomb’s law provided that
(a) the charges are not too small
(b) the charges are in a vacuum
(c) the charges are not too large
(d) linear dimensions of the bodies are much smaller than the distance between the bodies
6. An electric field can deflect
(a) y-rays
(b) X-rays
(c) neutrons
(d) a-particles
7. A body can be -vely charged by
(a) removing some neutrons
(b) removing some electrons
(c) giving some protons
(d) giving excess of electrons to it
8. The electric intensity at a point varies as r4 for
(a) an electric dipole
(b) a plane infinite sheet of charge
(c) a point charge
(d) a line charge of infinite length
9. If a glass rod is rubbed with silk, it acquires a +ve charge because
(a) electrons are added to it
(b) protons are added to it
(c) protons are removed from it
(d) electrons are removed from it
10. A pellet carrying charges of 0.5 coulombs is accelerated through a potential of 2000 volts. It attains a kinetic energy equal to
(a) 500 ergs
(b) 1,000 ergs
(c) 1,000 joules
(d) 1000 kilowatt hour
11. If a charge is moved against the coulomb’s force of an electric field
(a) energy is used from some outside source
(b) work is done by the electric field
(c) the strength of the field is decreased
(d) the strength of the field is increased
12. Electric intensity at a point varies as r4 for
(a) a line charge of infinite length
(b) a point charge
(c) an electric dipole
(d) a plane infinite sheet of charge
13. No current flows between two charged bodies when connected, if they have the same
(a) charge (b) potential
(c) capacity
(d) none of the above
14. Inside a hollow spherical conductor, the potential
(a) varies inversely as the square of the distance from the centre
(b) is constant
(c) varies directly as the distance from the centre.
(d) varies universally as the distance from the centre
15. An electric cell does 5 joules of work in carrying 10 coulombs of charge around a closed circuit. The e.m.f. of the cell is
(a) 1 volt
(b) 4 volt
(c) 1/2 volt
(d) 2 volt
16. As one penetrates a uniformly charged sphere, the electric field strength E
(a) is zero at all points
(b) remains the same as at the surface
(c) increases
(d) decreases
17. Certain substances 1oe their electrical resistance at very low temperature. These substances are called
(a) dielectric
(b) good conductors
(c) semiconductors
(d) superconductors
18. Sixty-four charged drops of capacity C and potential V are put together to form a bigger drop If each small drop has charge q, the charge on the bigger drop will be
(a) 64q
(b) 4q
(c) q
(d) 16q
19. Van de Graff generator is used to produce
(a) high voltage and high current
(b) high voltage and low current
(c) low voltage and low current
(d) low voltage and high current
20. An electric dipole is kept in a non-uniform electric field. It experience
(a) a force but not a torque
(b) a force and a torque
(c) a torque but not a force
(d) neither a force nor a torque
21. Two charged spheres of radii 10 cm and 15 cm are connected by a thin wire. No current will flow if they have the
(a) same energy
(b) same potential
(c) same field on their surfaces
(d) same charge on each
22. A conductor with a +ve charge
(a) is always at zero potential
(b) is always at +ve potential
(c) is always at -ve potential
(d) may be at +ve, zero or -ve potential
23. A point charge of 40 stat coulomb is placed 2 cm in front of an earthed metallic plane plate of a large size. Then the force of attraction on the point charge is
(a) 1600 dynes
(b) 160 dynes
(c) 400 dynes
(d) 100 dynes
24. If an electron has an initial velocity in a direction different from that of an electric field, the path of an electron is
(a) a circle
(b) an ellipse
(c) a parabola
(d) a straight line
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