Question

A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be

• A. four times
• B. doubled
• C. halved
• D. one fourth

Hint:

When a coil is cut into equal parts, the resistance of each part decreases, and the power (heat) generated increases because power is proportional to the square of the current and resistance.

Answer 1

The Correct Option is B

Step 1: The heat generated in a coil is given by the formula: \[ H = I^2 R \] where \( I \) is the current and \( R \) is the resistance. 
Step 2: When the coil is cut into two equal parts, the resistance of each part becomes half of the original coil's resistance. Therefore, the heat generated by the coil when used in the heater will double. 
Step 3: If the current remains constant, the heat generated by one part of the coil is double that of the original coil.