Question

True or false: (a) The induced emf in a circuit is proportional to the magnetic flux through the circuit. (True/False) (b) There can be an induced emf at an instant when the flux through the circuit is zero. (True/False) (c) Lenz's law is related to the conservation of energy. (True/False) (d) The inductance of a solenoid is proportional to the rate of change of the current in it. (True/False)

Answer 1

Step-by-step explanation:

(a) The induced emf in a circuit is given by :

`\epsilon=(-d\phi)/(dt)`

The induced emf in a circuit is proportional to the rate of change of magnetic flux through the circuit. So, the given statement is false.

(b) If the flux through the coil is constant, the induced emf is equal to zero. When the flux through the circuit is zero, there would be an induced emf. So, the statement is true.

(c) Lenz's law is related to the conservation of energy. It is a correct statement. According to this law, the direction of induced emf is such that it opposes the actual direction of actual emf.

(d) The inductance of a solenoid is given by :

`L=(\mu_o N^2A)/(l)`

The inductance of a solenoid is proportional to the rate of change of the current in it. It is false.