Question

What is the unit of specific resistance? A resistance of 25 \( \Omega \) is connected to a 12-volt battery. Calculate the heat energy in joules generated per minute.

Hint:

Heat energy (\( H \)) in a resistor is calculated using \( H = I^2 R t \).

Answer 1

The unit of specific resistance (resistivity) is \( \Omega \text{m} \). To calculate heat energy generated per minute, use Joule's law of heating: \[ H = I^2 R t \] First, find the current using Ohm's law: \[ I = \frac{V}{R} = \frac{12}{25} = 0.48 \text{ A} \] Now, calculating heat energy: \[ H = (0.48)^2 \times 25 \times 60 \] \[ H = 345.6 \text{ J} \]