Question

Two bulbs of 500Watt and 100Watt are connected parallel in a circuit of 250volt 1.Through which bulb is current greater?
2.Find out the residence of filaments in each bulb ?

Answer 1

Answer:1.Current is greater in the first bulb.

2.The resistance of the first bulb is 125 ohm and the resistance of the second bulb is 625 ohm.

Explanation:1.As, P(power)= VI, so I(current)= P/V.

So the current through the first bulb = 500/250= 2A

And the current through the second bulb = 100/250=0.4 A

So the current through the first bulb is greater.

2.As, P(power)=(V^2)/R, so R(resistance) = (V^2)/P.

So the resistance of the filament of the first bulb = (250^2)/500= 125 ohm

And the resistance of the filament of the second bulb= (250^2)/100=625 ohm.

Answer 2

Explanation:

As bulbs are in parallel both get same voltage

w= 500 = 250 × I ..... I = current

I = 500/250 = 2 amp

Resistance = V/ I

= 250/2

= 125 ohms

for the other bulb

w = 100 = 250 × I

I = 100 /250 = 0.4 amp

Resistance = V/ I

= 250/0.4

= 250 ×10 ÷4

= 625 ohms