Exams › NEET › Physics

The current passing through a choke coil of 5 henry is decreasing at the rate of 2 ampere per second. The e.m.f. developed across the coil is

1. 10 V
2. – 10 V
3. 2.5 V
4. – 2.5 V

Correct answer: 10 V

Solution

For an inductor, the induced emf is $e=-L\,di/dt$. Here $L=5$ H and the current is decreasing at 2 A/s, so $di/dt=-2$ A/s. Therefore $e=-5(-2)=10$ V.

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 →