Ans : No , We can not test an electric field by any charge . The test charge should so small that the distribution of the prime charge on the carrier conductor remains unaffected .
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 .
Ans : Place the smaller one inside the bigger one . As potential inside a hollow conductor is same as that of its surface , the potential inside the hollow conductor is now 100 V . The potential of the smaller conductor is now 100 + 50 = 150 V . Connect the two conductors by a wire . Charge will flow from the smaller one to the bigger one as the smaller one is at 150 V and the bigger one is at 100 V .
Scientific Reasoning : 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 .