Q139 / 150 · MHT CET 2025 (20 Apr Shift 2) · Physics
Three inductances are connected as shown in the figure. The equivalent inductance between $A$ and $B$ is


- A$2 \cdot 25 \mathrm{H}$
- Correct answerB$1 \cdot 20 \mathrm{H}$
- C0.225 H
- D0.120 H
Solution
Equivalent inductance between points A and B
The circuit contains two 0.7 H inductors in parallel, which are then in series with a 0.85 H inductor.
For parallel inductors, the equivalent is $L_p = \frac{L_1 \cdot L_2}{L_1 + L_2} = \frac{0.7 \cdot 0.7}{0.7 + 0.7} = \frac{0.49}{1.4} = 0.35$ H.
The total inductance is then $L_{eq} = L_p + L_3 = 0.35 + 0.85 = 1.20$ H.
This matches option B of $1.20$ H.
Hence, the correct answer is option: 'B'.