Hema uses two appliances in her home. One appliance is rated at 100 W and operates at 220 V, while the other appliance is rated at 60 W and also operates at 220 V. These appliances are connected to the electrical main supply in both series and parallel configurations, as shown in the figure 1 and 2.

(a) Calculate the total power consumption when the two appliances are connected in series.

(b) Calculate the total power consumption when the two appliances are corrected in parallel.

(c) Which configuration results in higher total power consumption, series or parallel?

(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?

An electric heater of power 780 W raises the temperature of 5.5 kg of a lab-chemical from 30°C to 41°C in 1.5 min.

Calculate

(a) energy supplied by heater,

(b) heat capacity and

(c) the specific heat capacity of the lab-chemical.

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)