Question

The filament of a light bulb has a resistance of 250 ohms. When the bulb is on, it draws a current of 0.4 amperes. How much power does the bulb consume?

A. 625 W
B. 100 W
C. 40 W
D. 10 W

Answer 1

The power consumed by the light bulb with a resistance of 250 ohms and a current of 0.4 amperes is 40 watts (W), answer option C.

Step-by-step explanation:

The question is asking to calculate the power consumption of a light bulb with a given resistance and current. The power consumed by an electrical device can be calculated using the formula Power (P) = Voltage (V) x Current (I). Alternatively, since power is also equal to the square of the current (I) multiplied by the resistance (R), the formula P = I2R can be used. Given that the light bulb has a resistance (R) of 250 ohms and a current (I) of 0.4 amperes flowing through it, the power consumption can be calculated as follows:

Power (P) = Current (I) x Current (I) x Resistance (R)

P = 0.4 A x 0.4 A x 250 Ω

P = 0.16 A2 x 250 Ω

P = 40 watts (W)

Therefore, the correct answer is C. 40 W.