The energy dissipated as heat in a resistor is given by MCQ with Answer and Explanation

The energy dissipated as heat in a resistor is given by
A. All of the above
B. V²t/R
C. I²Rt
D. VIt
Answer: Option A
Solution (By JKSSB Mock Tests)
All expressions equivalent (Joule's law).

Discuss this Question (0)

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

Practice More Physics Questions

Question #1
Which of the following is a derived unit?
A. Second
B. Candela
C. Kilogram
D. Newton

Correct Answer: Option D


Explanation:
Newton = kg·m/s², derived from base units. Kilogram, second, candela are base units. Derived units expressed in terms of base units. Joule, watt, pascal are also derived.

This question belongs to: Science Physics
Question #2
The efficiency of a Carnot engine depends on:
A. Size of the engine
B. Both (a) and (b)
C. Working substance
D. Temperatures of source and sink only

Correct Answer: Option D


Explanation:
Carnot efficiency η = 1 - T₂/T₁, depending solely on absolute temperatures of heat source (T₁) and sink (T₂). It is independent of working substance, engine size, or other details. This universality makes Carnot cycle the theoretical maximum efficiency benchmark. Memory tip: 'Carnot efficiency: only T_hot and T_cold matter; real engines have lower efficiency'. This thermodynamics concept is frequently tested in competitive exams. Always recall that Carnot efficiency is an ideal limit; real engines have additional losses reducing efficiency below this value.

This question belongs to: Science Physics
Question #3
The magnetic field at the center of a circular coil of radius R carrying current I is:
A. μ₀I/(4R)
B. μ₀NI/(2R)
C. μ₀I/(2R)
D. μ₀NI/(4πR)

Correct Answer: Option B


Explanation:
For a circular coil with N turns, magnetic field at center B = μ₀NI/(2R). For single turn (N=1), B = μ₀I/(2R). This derives from Biot-Savart law. Option A is for single turn; B and D have incorrect constants. Memory tip: 'Coil center: B = μ₀NI/(2R); straight wire: B = μ₀I/(2πr)'. This formula application is frequently tested in magnetism sections of competitive exams. Always note number of turns N; competitive exams often include it to test attention to detail.

This question belongs to: Science Physics