Question

Light bulb A is rated at 60 W and light bulb B is rated at 100 W. Both are designed to operate at 110 V. Which statement is correct?

Answer 1

Option 5:

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

Step-by-step explanation:

We have to compare the resistance and current of both bulbs.

Bulb A

Power = 60 W

Voltage = 110 V

Power is given as:

`P = V^2 /R`

where V= voltage and R = resistance

`=> 60 = 110^2 / R\\\\R = 201.6 \Omega`

Power is also given as:

P = IV

where I = current

=> 60 = I * 110

I = 60/110 = 0.54 A

Bulb B

Power = 100 W

Voltage = 110 V

To get resistance:

`100 = 110^2 / R\\\\R = 121 \Omega`

To get current:

100 = I * 110

I = 100 / 110

I = 0.91 A

Therefore, by comparison, the 60W bulb has a greater resistance and a lower current.