A gold leaf electroscope is to be charged positively by conduction. For this:

1. a positively charged rod is held close to the disc of electroscope
2. a positively charged rod is placed in contact with the disc of electroscope
3. a negatively charged rod is held close to the disc of electroscope
4. a negatively charged rod is touched with the disc of electroscope

A glass rod rubbed with silk is touched with the disc of a negatively charged gold leaf electroscope. The divergence of leaves will:

1. decrease
2. increase
3. remain unchanged
4. first decreases and then increases

Lightning conductor is made up of:

1. copper
2. glass
3. ebonite
4. wood

What do you understand by electricity at rest?