Physical properties of materials

A hydrogen-inflated polythene balloon is released from the surface of the Earth. As the balloon rises to an altitude up in the atmosphere, it will—

What happens when some charge is placed on a soap bubble?

Four wires of same material and dimensions as mentioned below are stretched by a load of same magnitude separately. Which one of them will be elongated maximum?

Consider the following statement— 1. If there were no phenomenon of capillarity, then it would be difficult to have a kerosene lamp. 2. One would not be able to use a straw to consume a soft drink. 3. The blotting paper would fail to function. 4. The big trees that we see around would not have grown on the Earth. Which of the following statements given above are correct?

For which one of the following capillarity is not the only reason?

Kerosene rises in the wick of the stove is due to—

In a capillary tube a fluid rises more as compared to water, it is due to :

When an air bubble at the bottom of lake rises to the top, it will—

While travelling by plane, the ink of the pen starts to come out—

In automobile hydraulic brakes work on—