Home
Class 12
PHYSICS
Asseration:Lenz's law violates the princ...

Asseration:Lenz's law violates the principle of conservation of energy.
Reason: Induced e.m.f. opposes always the change in magnetic flux responsible for its production.

A

Assertion is correct, reason is correct, reason is a correct explanation for assertion.

B

Assertion is correct, reason is correct, reason is not a correct explanation for assertion

C

Assertion is correct, reason is incorrect

D

Assertion is incorrect, reason is correct

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze the assertion and reason provided: **Assertion:** Lenz's law violates the principle of conservation of energy. **Reason:** Induced e.m.f. opposes always the change in magnetic flux responsible for its production. ### Step-by-Step Solution: 1. **Understanding Lenz's Law:** - Lenz's law states that the direction of the induced electromotive force (e.m.f.) is such that it opposes the change in magnetic flux that produced it. This is a consequence of the conservation of energy. 2. **Analyzing the Assertion:** - The assertion claims that Lenz's law violates the principle of conservation of energy. However, this is incorrect. Lenz's law actually supports the conservation of energy by ensuring that the induced e.m.f. works against the change in magnetic flux. 3. **Understanding the Reason:** - The reason states that induced e.m.f. always opposes the change in magnetic flux responsible for its production. This is a correct statement and is a fundamental aspect of Lenz's law. 4. **Conclusion:** - Since the assertion is incorrect (Lenz's law does not violate conservation of energy) and the reason is correct (induced e.m.f. opposes the change in magnetic flux), we conclude that the correct answer is that the assertion is false and the reason is true. ### Final Answer: - The assertion is incorrect, and the reason is correct. Therefore, the correct option is D.
To solve the question, we need to analyze the assertion and reason provided: **Assertion:** Lenz's law violates the principle of conservation of energy. **Reason:** Induced e.m.f. opposes always the change in magnetic flux responsible for its production. ### Step-by-Step Solution: 1. **Understanding Lenz's Law:** ...
Promotional Banner

Similar Questions

Explore conceptually related problems

Assertion: Faraday's laws are consequences of conservation of energy. Reason: In a purely resistive AC circuit, the current lags behind the e.m.f. in phase

STATEMENT-1: Lenz's law is based on the principle of conservation of energy. Because STATEMENT-2: The magnitude of the induced emf is directly proportional to the rate of change of the magnetic flux.

A : Total induced emf in a loop is not confined to any particular point but it is distributed around the loop in direct proportion to the resistances of its parts. R: In general when there is no change in magnetic flux, no induced emf is produced.

(A) : Self-inductance is called the inertia of electricity. (R) : Self-inductance is the phenomenon, according to which an opposing induced e.m.f. is produced in a coil as a result of change in current or magnetic flux linked with the coil.

Statement-1 : The induced e.m.f. and current will be same in two identical loops of copper and aluminium, when rotated with same speed in the same magnetic field. Statement-2 : Induced e.m.f. is proportional to rate of change of magnetic field while induced current depends on resistance of wire.

The phase difference between the flux linkage and the induced e.m.f. in a rotating coil in a uniform magnetic field

(a) Describe a simple experiment (or activity) to show that the polarity of emf induced in a coil is always such that it tends to produce a current which opposes the change of magnetic flux that produces it. (b) The current flowing through an inductor of self inductance L is continuously increasing. Plot a graph showing the variation of (i) Magnetic flux versus the current (ii) Induced emf versus dI/Dt (iii) Magnetic potential energy stored versus the current.

Asseration: The direction of induced e.m.f. is always such as to oppose the change that causes it. Reason: The direction of induced e.m.f. is given by Lenz's Law.

Asseration: Induced potential across a coil and therefore induced current is always opposite to the direction of current due to external source. Reason: Lenz's law states that it always opposes the cause due to which it is being produced.

Electromagnetic brakes work on the principle of electromagnetic induction. If a metallic disc or a coil is rotating in a uniform magnetic field, it will experience a torque due to induced currents set up in the disc. According to Lenz's law, induced current is in a direction so as to oppose the rotation. Hence a retarding torque is produced. The rotating wheel of a vehicle is connected to a coil placed in a uniform emf is used to charge a battery. Thus kinetic enery of wheel is stored as chemical energy. The drawback of electromagnetic brake is that induced current or retarding torque is directly proportional to speed of rotation. The speed, therefore, decays exponentially and vehicle will take a long time to stop. Thus, mechanical brakes are used simultaneously. The advantage of electromagnetic brakes is that