State the functions of the following in a nuclear reactor:-

i) Mention two important precautions that should be taken while handling radioactive materials.

ii) State any one use of radioisotopes. 

The combination of a movable pulley P₁ with a fixed pulley P₂ is used for lifting up a load W.

i) State the function of the fixed pulley P₂.

ii) If the free end of the string moves through a distance C, find the distance by which the load W is raised.

iii) Calculate the force to be applied at C to just raise the load W = 20 kgf, neglecting the weight of the pulley P₁and friction. 

A solid body weighs 2.10 N in air. Its relative density is 8.4. How much will the body weigh if placed:-

i) in water,

i) What is meant by refraction?

ii) Express the refractive index n of a medium,

1. In terms of the velocity of light.
2. In terms of the angle of incidence 'i' in air and the angle of refraction 'r' in a denser medium.

36.

If there is no heat loss to the surroundings, the heat released by the condensation of m₂ g of ice at 0^oC into water at 0^o C.

i) Find:

1. The heat lost by the steam in terms of m_1.

2. the heat gained by ice in terms of m₂.

ii) Form a heat equation and find the ratio of m₂: m₁ from it.

In the figure given alongside, A, B and C are three ammeters. The ammeter B reads 0.5 A. All the ammeters have negligible resistance.

 

Calculate:

i) The readings in the ammeter A and C.

i) Draw a labeled diagram of a hot cathode ray tube.

ii) Why are materials of low work function preferred as thermionic cathode materials?