A closed container of water at \(30^\circ \text{C}\) is opened while on the surface of the moon. What will happen to the water?

1.	The water will boil.
2.	The water will form a spherical ball.
3.	The water will freeze.
4.	The water will split (break down) into hydrogen and oxygen.

The thermal expansion of a solid is due to the:

Mark the correct statement(s) of the following.

A piece of hot copper at \(100~^\circ \text{C}\) is plunged into a pond at \(30~^\circ \text{C}\). The copper cools down to \(30~^\circ \text{C}\) while the pond being huge stays at its initial temperature. Then:

A thin paper cup filled with water does not catch fire when placed over a flame. This is because:

Mercury is often used in clinical thermometers. Which one of the following properties of mercury is not a reason for this?

Two rods of the same length and the same area of the cross-section are joined. The temperature of the two ends is shown in the figure.

As we move along the rod, temperature varies as shown in the following figure.
                
Then:
1. \(K_{1}>K_{2}\)
2. \(K_{1}=K_{2}\)
3. \(K_{1}<K_{2}\)
4. none of these

Two identical balls, \(A\) and \(B\) of uniform composition are initially at the same temperature, each absorbs exactly the same amount of heat. Ball \(A\) is hanging down from the ceiling by a massless inextensible thread while ball \(B\) rests on the horizontal floor in the same room. Assuming no subsequent heat loss by the balls, which of the following statements is correct about their final temperatures, \(T_A\) and \(T_B,\) once the balls have reached their final dimension?

1. \(T_A<T_B\)
2. \(T_A>T_B\)
3. \(T_A=T_B\)
4. \(T_A\leq T_B\)

A rod \(\mathrm{A}\) has a coefficient of thermal expansion \((\alpha_A)\) which is twice of that of rod \(\mathrm{B}\) \((\alpha_B)\). The two rods have length \(l_A,~l_B\) where \(l_A=2l_B\). If the two rods were joined end-to-end, the average coefficient of thermal expansion is: