Physics 2006 JAMB Past Questions - Question 25: An electric heater with a p.d. of 240 V connected across its terminals has a total resistance of 960 Q. Find the power rating of the heater

Correct Answer

C

Explanation

To find the power rating of the electric heater, you can use the formula for electrical power, which is given by:

Power (P) = Voltage (V) * Current (I)

In this case, you are given the potential difference (p.d.) or voltage (V) as 240 volts, and you can find the current (I) by using Ohm's law:

Ohm's Law: V = I * R

Where:
- V is the voltage (240 V)
- I is the current
- R is the resistance (960 Ω)

To find the current (I):

I = V / R
I = 240 V / 960 Ω
I = 1/4 A
I = 0.25 A

Now that you have the current (I), you can calculate the power (P):

P = V * I
P = 240 V * 0.25 A
P = 60 watts

So, the power rating of the electric heater is 60 watts.