Exams › NEET › Physics

Induced e.m.f. in the loop is given by e = -B dA/dt = -B π 2r dr/dt. r = 2 cm = 2 × 10⁻² m, dr = 2 mm = 2 × 10⁻³ m, dt = 1 s.

1. e = 0.32 × π × 10⁻⁵ V = 3.2 × π μV
2. e = 0.32 × π × 10⁻⁶ V = 3.2 × π μV
3. e = 0.32 × π × 10⁻⁷ V = 3.2 × π μV
4. e = 0.32 × π × 10⁻⁸ V = 3.2 × π μV

Correct answer: e = 0.32 × π × 10⁻⁶ V = 3.2 × π μV

Solution

The induced e.m.f. is calculated using the formula e = -B dA/dt = -B π 2r dr/dt. Substituting r = 2 × 10⁻² m, dr = 2 × 10⁻³ m, and dt = 1 s, we get e = π × 2 × (2 × 10⁻²) × (2 × 10⁻³) = 0.32 × π × 10⁻⁶ V = 3.2 × π μV.

Related NEET Physics questions

• Which of the following statement regarding transformer is incorrect?
• Which one of the following statements is true?
• Which statement is incorrect related to induced electric field due to changing magnetic flux?
• A dynamo produces an electric current. It is based on the principle:
• In electromagnetic induction, the induced E.M.F is independent of
• A conductor is moved in a varying magnetic field. Name the law which determines the direction of current induced in the conductor:

⚔️ Practice NEET Physics free + battle 1v1 →