Question

Two electric bulbs have resistances in the ratio 1 : 2. If they are joined in series, the
energy consumed in these are in the ratio _________.
i) 1 : 2
ii) 2 : 1
iii) 4 : 1
iv) 1 : 1

Answer 1

Hey mate


Let the voltage be V across both the bulbs.And resistance of first bulb is R; hence resistance of second bulb is 2R.

So if we find the ratio of powers we have

V^2/R : V^2/2R

= 1 : 1/2

= 2 : 1

the correct option is option( ii)

Hope it helps to you.

Answer 2

Dear Student,

◆ Answer -

(i) 1 : 2

● Explanation -

In series combination of bulbs, equal current is passing through both bulbs.

Energy consumed by the bulb in time t is given by -

E = I²Rt

For two bulbs in series,

E1/E2 = I²R1t / I²R2t

E1/E2 = R1/R2

Substitute R1/R2 = 1/2,

E1/E2 = 1/2

Therefore, the

energy consumed by the bulbs is in the ratio 1 : 2.

Thanks dear. Hope this helps you...