Question

Question 9:
Consider the circuits given below :

(a) In which circuit are the lamps dimmest ?
(b) In which circuit or circuits are the lamps of equal brightness to the lamps in circuit (/) ?
(c) Which circuit gives out the maximum light ?

Lakhmir Singh Physics Class 10

Answer 1

(a) In circuit (ii), the lamps are dimmest.

(b) In circuit (iii) the lamps are equal brightness in circuit (i) as both are connected in parallel.

(c) in circuit, (ii), gives out the maximum light.

explanation : generally, brightness or dimness depends on power supplied to appliances (i.e., lamp or bulb), lamp will be more brighter when it gets more power.

in case of series combination, power supplied decreases due to increase equivalent resistance. hence, lamp will be dimmer when resistors are joined in series combination.

but in case of parallel combination, power increase due to decrease equivalent resistance. hence, lamp will be brighter when resistors are joined in parallel combination.

Answer 2

Solution :

(a) circuit (ii)

(b) circuit (iii)

(c) circuit (iii)