A 240V bulb passes a current of 4A. Calculate the power in the lamp.

MCQ-1 A 240V bulb passes a current of 4A. Calculate the power in the lamp.

(A) 950 W

(B) 960 W

(C) 930 W

(D) 850 W


Ans: (B) 960 W


Explanation:

Here Voltage V = 240 V

Current I = 4 A

Power P = ?


Power P = Voltage V * Current I

= 240 V * 4 A

= 960 W

The power in a lamp is 960 W.


MCQ-2 A current of 8A flows in a resistor of 4 ohms. Calculate the energy dissipated in 600 seconds in the resistor.

(A) 155.7 Killo Joule

(B) 156.3 Killo Joule 

(C) 153.6 Killo Joule

(D) 152.5 Killo Joule


Ans:(C) 153.6 Killo Joule

Explanation:

Here Current I = 8 A

Resistance R = 4 ohm 

Time T = 600 seconds

Energy E = ?

Power P = I2R

                = 8 * 8 * 4

                = 256 W

So power is 256 W 

Now Energy E = Power P * Time T 

                           = 256 * 600

                           = 153600 Joule

                           = 153.6 Kilo Joule

Hence the power dissipated in resistor is 153.6 Kilo Joule