Question

Two light bulbs are operated at a potential difference of 110 V. Light bulb A produces 60 W of power and light bulb B produces 100 W of power. Which statement below is correct?

a. The 60 W bulb has a greater resistance and smaller current than the 100 W bulb.

b. The 60 W bulb has a smaller resistance and smaller current than the 100 W bulb.

c. The 60 W bulb has a greater resistance and greater current than the 100 W bulb.

d. The 60 W bulb has a smaller resistance and greater current than the 100 W bulb.

Answer 1

Answer:a

Step-by-step explanation:

Given

Potential difference
`V=110\ V`

Power of bulb A
`P_A=60\ W`

Power of bulb B
`P_B=100\ W`

If voltage is same for both the bulbs then Power is given by

`P=(V^2)/(R)`

`P_A=((110)^2)/(R_A)`

`60=(110^2)/(R_A)`

`R_A=201.66\ \Omega`

similarly

`R_B=(110^2)/(100)`

`R_B=121\ \Omega`

`R_A>R_B`

so current in bulb A is smaller than B

Thus the 60 W bulb has a greater resistance.

Thus option (a) is correct