When a conducting soap bubble is negatively charged then
Its size starts varying arbitrarily
It expands
It contracts
No change in its size takes place
A polythene piece rubbed with wool is found to have a negative charge of $3 \times 10^{-7} \;C$
$(a)$ Estimate the number of electrons transferred (from which to which?)
$(b)$ Is there a transfer of mass from wool to polythene?
A glass rod rubbed with silk is used to charge a gold leaf electroscope and the leaves are observed to diverge. The electroscope thus charged is exposed to $X$-rays for a short period. Then
What are called conductors and non-conductors ? In which free electrons are more ? Conductor or non-conductor.
Write the law of conservation of charge. Give one example.
Why the metal rods can’t be charged by holding them in hands ?