Three incandescent bulbs of `100 W` each are connected in series in an electric circuit. In another circuit, another set of three bulbs of the same wattage are connected in parallel to the same source.
(a) Will the bulbs in the two circuits glow with the same brightness ? Justify your answer.
(b) Now let one bulb in both circuits get fused. Will the rest of the bulbs continue to glow in each circuit ? Give reason.
(a) In a household electric circuits, different appliances are connected in parallel to one another. Give two reasons for the same.
(b) An electrican puts a fuse of rating `5 A` in that part of domestic electrical circuit in which electrical heater of rating `1.5 kW, 220 V` is operating. What iis likely to happen in this case and why ? What change, if any, needs to be made ?

Explanation

N/A
or
(a) Different appliancies in a household electric circuit are connected in parallel so that :
(i) the appliancies work at the same voltage.
(ii) the appliancies can be operated independent of each other.
(b) Here `P = 1.5 kW = 1500 W, V = 220 V`
As `P = VI, I = (P)/(V) = (1500)/(220) = 6.81 A`
When `6.81 A` current flows through the fuse-wire of rating `5 A`, it melts and the circuit breaks. This is due to the reason that the current flowing through the fuse, i.e., `6.81 A` is more than its rating, i.e., `A`. In this case, a fuse of rating higher than `6.81 A` (i.e., say `10 A`) must be used.