Lim Si Hui asked in Physics

can help me with this qns.

Q5. The live wire of a 240 V mains supply is protected by a 15A fuse, A 3.0 kW heater is connected to the supply. The arrangement is shown in Fig.5.1.
  (a) Name the wires P, Q and R.
          Fully describe the function of the earth wire.

  (b) The user wishes to connect a 2.0 kW heater in parallel with the 3.0 kW heater shown in Fig.5.2. Discuss, using suitable calculations, whether this would be a sensible idea.

(c) The element in the heater is made of metal. Use kinetic theory to describe the effect on the atoms of the metal as the temperature rises.

Thank You

Sachin Kumar Mittal answered this

As we can see R is just connected to metal wire so that if any current is there may reach to earth (0 potential).P is live wire having potential of 220 v and q is neutral wire which complete the circuit.we can if only if current overflow fuse will start operating and supply will be stopped.......we can also see from 2 nd circuit all the connections are repeated ,it is parallel circuit....... disclaimer....please add different questions in different post.....