Question

Two light bulbs P and Q are identical in all aspects, except that P's filament is thicker than Q's. If the same potential difference is applied to each, then:

• A. Q will burn brighter because it has the greater resistance.
• B. P will burn brighter because it has the lower resistance.
• C. Q will burn brighter because it has the lower resistance.
• D. P will burn brighter because it has the greater resistance.

Answer 1

The correct option is B

P will burn brighter because it has the lower resistance.

Resistance is inversely proportional to the area of cross-section. Hence, a thicker filament will have low resistance and in accordance with Ohm's law, more current will pass through it and it will glow brightly.