Consider the following observations:
1. A circular metallic disc has a circular hole at its centre. When the disc is heated, the diameter of the hole will decrease
2. A common fluorescent tube contains mercury vapour at high pressure
Which among the above is / are correct?

Answer: [D] Neither 1 nor 2

The first statement is not correct. When you heat a circular disc with a hole in its center; the diameter of the hole would increase. However, if the hole is smaller in comparison to the overall size of the disc, it may also get skewed (due to differential heating of the disc. )

The second statement is not correct because  fluorescent lamp tube is filled with a gas containing low pressure mercury vapor and argon, xenon, neon, or krypton. The pressure inside the lamp is around 0.3% of atmospheric pressure.

This question is a part of GKToday's Integrated IAS General Studies Module