When a coil is connected to a d.c. source of | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) For a $d.c.$ source,the inductor acts as a simple resistor because the frequency is zero. Thus,the resistance $R$ is given by $R = \frac{V}{I} = \

Vedclass · Accepted Answer

$\frac{4}{\pi} 	imes 10^{-2} \ H$

Vedclass · Answer

(C) For a $d.c.$ source,the inductor acts as a simple resistor because the frequency is zero. Thus,the resistance $R$ is given by $R = \frac{V}{I} = \frac{12 \ V}{4 \ A} = 3 \ \Omega$.For an $a.c.$ source,the impedance $Z$ is given by $Z = \frac{V}{I} = \frac{12 \ V}{2.4 \ A} = 5 \ \Omega$.The impedance of an $RL$ circuit is $Z = \sqrt{R^2 + X_L^2}$,where $X_L$ is the inductive reactance.Squaring both sides,$Z^2 = R^2 + X_L^2$,so $X_L^2 = Z^2 - R^2 = 5^2 - 3^2 = 25 - 9 = 16$.Thus,$X_L = 4 \ \Omega$.Since $X_L = 2 \pi f L$,we have $L = \frac{X_L}{2 \pi f} = \frac{4}{2 \pi 	imes 50} = \frac{4}{100 \pi} = \frac{4}{\pi} 	imes 10^{-2} \ H$.

When a coil is connected to a $d.c.$ source of $e.m.f.$ $12 \ V$,the current of $4 \ A$ flows in it. If the same coil is connected to a $12 \ V, 50 \ Hz$ $a.c.$ source,the current flowing in it is $2.4 \ A$. The self-inductance of the coil will be:

Similar Questions

$A$ sinusoidal voltage of peak value $283\,V$ and frequency $50\,Hz$ is applied to a series $LCR$ circuit in which $R = 3\,\Omega$,$L = 25.48\,mH$,and $C = 796\,\mu F$. Find the impedance of the circuit in $\Omega$.

$A$ bulb connected in series with an air-core solenoid is lit by an $A.C.$ source. If a soft iron core is inserted into the solenoid,then

An $A.C.$ source is connected to a series $LCR$ circuit. If the voltage across $R$ is $40 \,V$, the voltage across $L$ is $80 \,V$, and the voltage across $C$ is $40 \,V$, then the e.m.f. '$e$' of the $A.C.$ source is:

In an $A.C.$ circuit,a resistance $R = 40 \ \Omega$ and an inductance $L$ are connected in series. If the phase angle between voltage and current is $45^{\circ}$,then the value of the inductive reactance is $(\tan 45^{\circ} = 1)$. (in $\Omega$)

In an $LCR$ series circuit, an alternating voltage source of frequency $F$ is connected. The current leads the voltage by $45^{\circ}$. The value of $L$ is

Vedclass Test Series

Exam Paper Generator

Online Exam Module