Question

Magnetic flux φ (in weber) linked with a closed circuit of resistance 10 ohm varies with time t (in seconds) as

$\phi = 5 t ^ { 2 } - 4 t + 1$

The induced electromotive force in the circuit at t = 0.2 sec. is

• A. 0.4 volts
• B. – 0.4 volts
• C. – 2.0 volts
• D. 2.0 volts

Answer 1

Answer: (D)

2.0 volts

Answer 2

$e = - \frac { d \phi } { d t } = - ( 10 t - 4 )$ ⇒