Question

Which one of the following options makes a bulb to glow more brightly?

• A. Bulb connected to one dry cell of 6 V.
• B. Bulb connected to 3 dry cells of 3 V each connected in series.
• C. Bulb connected to 3 dry cells of 1.5 V each connected in series.
• D. Bulb connected to 2 cells of 2 V each.

Answer 1

The correct option is B

Bulb connected to 3 dry cells of 3 V each connected in series.

Following image shows the series connection of the batteries,

So, in series, the net voltage is the sum of all voltages. In the case of 3 cells of 3 V each, we get 3 + 3 + 3 = 9 V. In this case, the bulb will glow with the greatest brightness. So the correct choice is choice B. Remaining options give the output less than 9 V. So, more voltage means more light (more energy released) from the filament.