EXPERIMENT (2)

B. Brightness of bulbs in a parallel circuit

Aim
To compare the brightness of bulbs in a parallel circuit

Problem
Is the brightness of bulbs in a parallel circuit affected by its number?

• What to change: The number of bulbs
• What to observe: The brightness of the bulbs
• What to keep the same: The type and number of dry cells, and The type of bulbs

Steps

1. Two similar parallel circuits are connected as shown in the diagram.
2. Circuit P has two bulbs while circuit Q has three bulbs.
3. Both circuits are switched on and the brightness of the bulbs is observed.

Observation

Circuit	Brightness of bulb
P (with two bulbs)	Both bulbs shine with similar brightness.
Q ( with three bulbs)	All the bulbs shine with similar brightness as in P

Conclusion
The brightness of bulbs remains the same when the number of bulbs in a parallel circuit is changed.