The Q factor of a resonant LCR circuit is measure of MCQ with Answer and Explanation

The Q factor of a resonant LCR circuit is measure of
A. Selectivity
B. Reactance
C. Impedance
D. Power factor
Answer: Option A
Solution (By JKSSB Mock Tests)
Higher Q means sharper resonance, better selectivity.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Physics Questions

Question #1
A car moving with speed 54 km/h is stopped in 5 s. The distance covered before stop is
A. 37.5 m
B. 27 m
C. 75 m
D. 54 m

Correct Answer: Option A


Explanation:
54 km/h = 15 m/s. u=15, v=0, t=5. a = (0-15)/5 = -3 m/s². s = ut+½at² = 15×5 + ½×(-3)×25 = 75 - 37.5 = 37.5 m. Or s = (u+v)/2 × t = 7.5×5 = 37.5 m.

This question belongs to: Science Physics
Question #2
Three resistors of 2Ω, 3Ω, and 6Ω are connected in parallel. The equivalent resistance is:
A. 6Ω
B. 1Ω
C. 0.5Ω
D. 11Ω

Correct Answer: Option B


Explanation:
For parallel combination: 1/R_eq = 1/R₁ + 1/R₂ + 1/R₃ = 1/2 + 1/3 + 1/6 = (3+2+1)/6 = 6/6 = 1. Thus R_eq = 1Ω. Note: Equivalent resistance in parallel is always less than the smallest individual resistance (here 2Ω). Memory tip: 'Parallel: reciprocal sum; result < min(R)'. This standard calculation tests parallel resistance formula application, frequently appearing in competitive exams. Always simplify fractions carefully; common denominator method avoids errors. Verify: 1Ω < 2Ω, consistent with parallel behavior.

This question belongs to: Science Physics
Question #3
A spring of force constant k is stretched by a length x. The work done in stretching it further by the same length x is:
A. 2kx²
B. ½kx²
C. ³/₂kx²
D. kx²

Correct Answer: Option C


Explanation:
Work done to stretch spring from 0 to x: W₁ = ½kx². Work done from 0 to 2x: W₂ = ½k(2x)² = 2kx². Thus work for additional stretch from x to 2x: ΔW = W₂ - W₁ = 2kx² - ½kx² = ³/₂kx². Spring force is variable (F=kx), so work is integral of F·dx, yielding parabolic energy storage. Memory aid: Elastic potential energy U = ½kx²; always calculate difference for incremental work. This problem tests understanding of work done by variable forces, a common theme in energy conservation questions in competitive exams.

This question belongs to: Science Physics