A 10   Ω ,   20   mH coil carrying constant current is connected to a battery of 20   V through a switch. Now after switch is opened current becomes zero in 100   μ s . The average e.m.f. induced in the coil is _____ V .

Question

A 10 &#160; &#937; , &#160; 20 &#160; mH coil carrying constant current is connected to a battery of 20 &#160; V through a switch. Now after switch is opened current becomes zero in 100 &#160; &#956; s . The average e.m.f. induced in the coil is _____ V .

Aicharya · Accepted Answer

The initial current in the coil will be, $i = \frac{V}{R} = \frac{20}{10} = 2 A$ .

Average e.m.f. developed in the coil will be,

$ε = - \frac{∆ ϕ}{∆ t} = \frac{0 - L i}{t} = \frac{20 \times 10^{- 3} \times 2}{100 \times 10^{- 6}} = 400 V$ .

A 10   Ω ,   20   mH coil carrying constant current is connected to a battery of 20…

Solution

A 10 &#160; &#937; , &#160; 20 &#160; mH coil carrying constant current is connected to a battery of 20…

Solution

A 10 Ω , 20 mH coil carrying constant current is connected to a battery of 20…