Two similar cells are used to light two similar lamps as illustrated in the diagrams above. In which of the circuit diagrams are the lamps brightest?
A.
P
B.
Q
C.
R
D.
S
Correct answer is B
The determinant of the brightness of a bulb is the power (watts) of the circuit.
Recall that Power (P) = \(\frac{V^2}{R}\).
Since the resistance is to be used as a divisor, it means the smaller the resistance, the greater the power.