Question

Three bulbs, each with a resistance of 180 Ω, are connected in parallel to an ideal battery of emf 60 V.
Find the current delivered by the battery when (a) all the bulbs are switched on, (b) two of the bulbs are switched on and (c) only one bulb is switched on.

Answer 1

Answer:

Explanation: When three bulb are on

Requivalent = 180/3 = 60

E.m.f = 60v

I = 60v/60ohm = 1A

Now when one is only switched on

R equivalent = 180ohm

Emf = 60v

i = 60v/180ohm = 1/3 A = 0.333 A