Home
Class 12
PHYSICS
A coil of resistance 20Omega and inducta...

A coil of resistance `20Omega` and inductance `0.5H` is switched to `DC200V` supply. Calculate the rate of increase of current
a. at the instant of closing the switch and
b. after one time constant.
c. Find the steady state current in the circuit.

Text Solution

Verified by Experts

This is the case of growth of current in an L-R circuit. Hence, current at time t is given by
`i=i_0(l-e^((-t)/tau_L))` rate of increase of current,
`(di)/(dt)=(i_0)/(tau_L)e^((-t)/(tau_L)), at t=0 (di)/(dt)=(i_0)/(tau_L)=(E//R)/(L//R)=E/L`
`(di)/(dt)=(200)/(0.5)=400 A//s`
(b) At `t=tau_L,(di)/(dt)(400)e^(-1)=(0.37)(400)=148 A//s`
(c ) The steady state current in the circuit is,
`i_o=E/R=(200)/(20)10A`
(e) smaller the time constant, quicker is the discharge of the condenser.
Promotional Banner

Topper's Solved these Questions

  • ELECTROMAGNETIC INDUCTION

    NARAYNA|Exercise EVALUATE YOURSELF -1|4 Videos

  • ELECTROMAGNETIC INDUCTION

    NARAYNA|Exercise EVALUATE YOURSELF -2|6 Videos

  • ELECTRO MAGNETIC WAVES

    NARAYNA|Exercise LEVEL-II(H.W)|14 Videos

  • ELECTROMAGNETIC WAVES

    NARAYNA|Exercise EXERCISE -4|15 Videos

Similar Questions

Explore conceptually related problems

In cirucit shown in figure-5.111, find the current through battery just after closing the switch and after a long time in steady state.

A coil having resistance 15 Omega and inductance 10H is connected across a 90 Volt dc supply. Determine the value of current after 2sec , What is the energy stored in the magnetic field at that instant.

A coil having a resistance of 50.0 Omega and an inductance of 0.5 H is connected to an AC source of 110 , v, 50Hz . The rms current in the circuit is

A coil of resistance 11Omega and inductance 0.1H is connected to a 110V d.c. mains. Find (i) the current finally established in the coil. (ii) the voltage used in overcoming the resistance when the rising current is 3A, and (iii) the rate at which the current is rising at that instant.

the resistance and inductance of series circuit are 5Omega and 20H respectively. At the instant of closing the switch, the current is increasing at the rate 4A-s . The supply voltage is

An inductor with an inductance of 2.5H and a resistance of 8Omega is connected to the terminals of a battery with an EMF 6V and negligible internal resistance. Find (a) The initial rate of increase of current in the circuit (b) The rate of increase of current at the instant when the current is 0.50A (c ) The current 0.25s after the circuit is closed (d) The final steady state current

Find power produced in 5 Omega resistance in steady state after closing the switch S :

A coil of inductance 2 H and resistance 10 Omega are in a series circuit with an open key and a cell of constant 100 V with negligible resistance. At time i = 0 , the key is closed. Find (a) the time constant of the circuit. (b) the maximum steady current in the circuit. (c) the current in the circuit at f =1 s .

In the circuit shown in figure-3.238, find the current in 6Omega resistance just after closing the switch S.

A coil of inductance 0.2 H and 1.0 W resistance is connected to a 90 V source. At what rate will the current in the coil grow at the instant the coil is connected to the source?