(a) State two common properties of γ-rays and X-rays.

(b) Name two main sources of nuclear radiations. How are the nuclear radiations harmful?

Five resistors of different resistances are connected together as shown in the figure.

A 12 V battery is connected to the arrangement.

Calculate

(a) total resistance in the circuit.

(b) the total current flowing in the circuit.

If a block (made of lead) of mass 500 g at 127°C is heated in a furnace till it completely melts. Determine the quality of heat required.

(a) to bring the block upto its melting point.

(b) total heat energy required to melt the block to its melting point.

(c) total heat energy required.

(Take, melting point of lead = 327°C, specific heat capacity = 0.13 Jg^-1°C^-1 and specific latent heat of fusion = 26 Jg^-1)

(a) List three methods of producing magnetic fields.

(b) Imagine that you are sitting in a chamber with your back to one wall. An electron beam moving horizontally from back wall towards the front wall is deflected by a strong magnetic field to your right side. What is the direction of magnetic field?

(c) Which rule is used to find the direction of magnetic field due to a current carrying conductor?