Question

3. A 250V bulb passes a current of 0.3A. Calculate the power in the lamp.

a) 75W
b) 50W
c) 25W
d) 90W

Answer 1

V = 250 V

I = 0.3 A

Power = V × I

Power = 250 × 0.3 ⇒ 75 W

∴ Answer is 75 W.

Answer 2

Given:

• Voltage = 250V
• Current = 0.3 A

To Find:

• The power of the lamp.

Solution:

The formula to find the power is given by,

P = V×I → {equation 1}

Where "V" is the voltage, "P" is the power, and "I" is the current.

On substituting the given values in equation 1 we get,

⇒ P = 250×0.3 {multiplying the terms}

⇒ P = 75 W {the S.I unit of power is Watts}

∴ The power of the lamp = 75 W. (option a)