Q.1. If a body has positive charge on it, then it means it has
(1) Gained some protons
(2) Lost some protons
(3) Gained some electrons
(4) Lost some electrons
Sol. Answer (4)
Due to lack of electron body get positive charge.
Q.2. Sure check for presence of electric charge is
(1) Process of induction
(2) Repulsion between bodies
(3) Attraction between bodies
(4) Frictional force between bodies
Sol. Answer (2)
Due to similar (like charge), repulsion force is possible but attraction force may be due to uncharged body.
Q.3. If a solid and a hollow conducting sphere have same radius then
(1) Hollow sphere will hold more maximum charge
(2) Solid sphere will hold more maximum charge
(3) Both the spheres will hold same maximum charge
(4) Both the sphere can’t hold charge
Sol. Answer (3)
Excess charge spread on outer surface only from their property.
Q.4. When a conducting soap bubble is negatively charged then
(1) Its size starts varying arbitrarily
(2) It expands
(3) It contracts
(4) No change in its size takes place
Sol. Answer (2)
Due to repulsion force between diametrically opposite wall, it expands.
Q.5. Five balls marked a to e are suspended using separate threads. Pairs (b, c) and (d, e) show electrostatic repulsion while pairs (a, b), (c, e) and (a, e) show electrostatic attraction. The ball marked a must be
(1) Negatively charged
(2) Positively charged
(3) Uncharged
(4) Any of the above is possible
Sol. Answer (3)
Q.6. When a plastic rod rubbed with wool is brought near the knob of a negatively charged gold leaf electroscope, the gold leaves
(1) Contract
(2) Dilate
(3) Start oscillating
(4) Collapse completely
Sol. Answer (2)
Q.7. Coulomb’s law is analogous to
(1) Charge conservation law
(2) Newton’s second law of motion
(3) Law of conservation of energy
(4) Newton’s law of gravitation
Sol. Answer (4)
Coulomb’s law and Newton’s law of gravitation are inverse square law.
Q.8. Two point charges Q1 and Q2 exert a force F on each other when kept certain distance apart. If the charge on each particle is halved and the distance between the two particles is doubled, then the new force between the two particles would be
(1) F/2
(2) F/4
(3) F/8
(d) F/16
Sol.
Q.9. Two equally charged identical small balls kept some fixed distance apart exert a repulsive force F on each other. A similar uncharged ball, after touching one of them is placed at the mid-point of line joining the two balls. Force experienced by the third ball is
(1) 4F
(2) 2F
(3) F
(4) F/2
Q.10. Two equal point charges A and B are R distance apart. A third point charge placed on the perpendicular bisector at a distance ‘d’ from the centre will experience maximum electrostatic force when
