Physics Q & A

Ans : Shock is produced by current flowing through the body of a man . When the man is inside a cage , he is at the same potential as the cage itself , so no current flows through his body when he touches the cage .

Q : Can two equipotential surfaces intersect ?

Ans : No , two equipotential surfaces can never intersect because if they intersect at a point , the electric field at a point can have two directions simultaneously , which is impossible .

Q . Ordinary rubber is an insulator . But the special rubber tyres of aircraft are made conducting . why is this necessary ?

Ans : To conduct away electricity produced by friction .

Ans : Place two conductors some distance apart in a given region . Connect them by a wire and then remove it . Now test the two conductors for any charge on them . If they are found to carry no charge , it means that the electric potential in the given region of space is constant .

Ans : To conduct away the charge produced by friction . This charge , unless conducted away to the earth , may produce sparks causing the explosives in the truck to catch fire and explode.