Question

Two electric bulbs whose resistances are in the ratio $1:3$ are connected in series, the power dissipated in them is in the ratio.

• A. 1:1
• B. 1:3
• C. 2:1
• D. 1:4

Answer 1

The correct option is B

1:3

Step 1: Given

The ratio of the resistances of the bulbs is $1:3$. This can be written as

$\frac{R_1}{R_2}=\frac{1}{3}$

Step 2: Calculate power dissipation ratio-

For the series combination, the power is directly proportional to the resistance

Power $P=I^{2}R$ where $I$ is the current

Therefore, the ratio of powers will be equal to the ratio of resistances

$\frac{P_1}{P_2}=\frac{R_1}{R_2}=\frac{1}{3}$

Hence, the correct answer is (B) i.e. 1:3.