Two objects are rubbed against each other, the nature of electric force, when they are placed at some distance is
Attractive
Repulsive
Both $(A)$ and $(B)$
Either $(A)$ or $(B)$
Discuss the method of charging of two spheres by without contact method.
Charge on $\alpha $ - particle is
A body can be negatively charged by
When ${10^{19}}$ electrons are removed from a neutral metal plate, the electric charge on it is
A charged gold leaf electroscope has its leaves apart by certain amount having enclosed air. When the electroscope is subjected to $X$-rays, then the leaves