Recent questions tagged electromagnetic-induction

Two coaxial solenoids are made by winding their insulated wire over a pipe of cross sectional area $A= 10\;cm^2$ length $20\;cm$ .One of the solenoids has 200 turns and another 400 turns. the mutual inductance is .

asked Mar 27, 2014 by meena.p

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Two induction coil of inductance $L_1$ and $L_2$ are separated by a considerable distance. On connectivity them in series the equivalent inductance is

asked Mar 27, 2014 by meena.p

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A circular loop of radius R, carrying current I lies in $X-Y $ plane with its centre at origin. The total magnetic flux through $X-Y$ plane is

asked Mar 27, 2014 by meena.p

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When a wire loop is rotated in a magnetic field, the direction of induced emf

asked Mar 26, 2014 by meena.p

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The current flowing in two coaxial coils is in the same direction. If we increase the distance between the two , the electric current will,

asked Mar 26, 2014 by meena.p

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A conducting ring of radius R is placed in a magnetic field perpendicular to the plane of the coil at the rate of $\beta$. Then Which one is correct ?

asked Mar 26, 2014 by meena.p

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A thin semicircular ring of radius 'a' is falling with its plane vertical to a horizontal magnetic field induction $\overrightarrow {B}$ .At the given position PQR the speed of ring is 'v' , the potential difference developed across the ring.

asked Mar 26, 2014 by meena.p

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A coil of inductance $L= 150\;mH$ and resistance $R= 70\;m \Omega$ is connected to a voltage source. How soon will the voltage attain $50\%$ of initial value

asked Mar 25, 2014 by meena.p

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A conducting rod of length $l=2\;cm$ moves with velocity 12 m/s at an angle $30^{\circ}$ to a magnetic field produced between two square faced poles of side 2 cm. If flux leaving the face is $5 \mu Wb$ the induces emf is

asked Mar 25, 2014 by meena.p

1 answer

A 1200 turn coil of mean area $500 \;cm^2 $ is held perpendicular to a uniform field of $4 \times 10^{-4}$ tesla. The resistance of coil is $20 \Omega$ . What will be the average induced current when coil turns through $180^{\circ}$ in $0.1\;$second?

asked Mar 25, 2014 by meena.p

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A metal rod of resistance $20 \;\Omega$ is fixed along the diameter of a conducting ring of radius$0.1 m$ . A magnetic field of $B=50T$ acts perpendicular to the plane The ring rotates with an angular velocity of $w=20\;rad/s$ about its axis . An external resistance of $10 \;\Omega$ is connected across center and rim of the ring. What is current through the external resistance.

asked Mar 24, 2014 by meena.p

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In the circuit given the switch is closed at time $t=0$ What is the amount of charge passing through the battery in are time constant ?

asked Mar 24, 2014 by meena.p

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In the given circuit shown : $L= 200\;mH;$ Emp of battery $E= 12 V$ $R_1=R_2=2 \Omega$ the internal resistance of battrey is negligible . The potential drop across the inductance L after time t.

asked Mar 24, 2014 by meena.p

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A emf of 10V is applied in a circuit containing inductance L and resistance R. $L=5H$ and $R= 10 \;\Omega$ . The ratio of current at $t =\infty$ and $t= 1\;s$ in

asked Mar 24, 2014 by meena.p

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A coil of inductance $84\;mH$ and resistance $8 \Omega$ is connected to $12 V$ battery. The current in the coil is 1 A at approximately

asked Mar 24, 2014 by meena.p

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A uniformly would soleacidal (ie) of self inductance $8 \times 10^{-4}\;H$ and resistance $45\;L$ is broken into two identical coils. These colis are then connected in parallel across a battery of $10V$ of negligible resistance the time constant for this circuit is

asked Mar 24, 2014 by meena.p

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A inductor $(L= 50 \;mH)$ and resistor of $R =100\;\Omega$ and a battery , of emf 100 V is initially connected in series. Then the battery is short circuited , the current flowing 1 ms after the short circuit is

asked Mar 21, 2014 by meena.p

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A conducting circular loop is placed in a uniform field of $B=0.05\;T$ with its plane perpendicular to the loop. The radius of loop is made to shrink at constant rate of $0.5\;mm$ per second. The induced emf when radius is $2 \;cm$ is

asked Mar 21, 2014 by meena.p

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A current $I= 10 \sin (100 \pi t)$ ampere is passed in first coil which induces a maximum emf of $5 \pi$ volts in second coil. The mutual inductance M is

asked Mar 21, 2014 by meena.p

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A circular coil of radius $30\; cm$ and resistance $\pi^{2}\;Ohms$ is rotating in a uniform magnetic field $B=10^{-2}$. Axis of rotation is diameter of coil which is perpendicular to direction of B. If Coil rotates with $200\;rpm$ the current induced in coil is

asked Mar 21, 2014 by meena.p

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A conducting rod AB of length 1 m is moving with uniform speed of $2\;m/s$ in a uniform magnetic field of 4T which is directed perpendicular to the plane of motion of the rod AB. A capacitor of capacity $C= 10\;\mu F$ is connected. The charge on the capacitor is

asked Mar 21, 2014 by meena.p

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A horizontal wire AB of length l is free to slide on a vertical conducting frame as shown. The wire has mass m and length l and resistance of circuit is R. The system is placed in a uniform magnetic field B directed perpendicular to the frame. The wire after falling a distance under the influence of gravity aquires a terminal speed equal to

asked Mar 21, 2014 by meena.p

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A conducting circular loop of radius a and resistance R is kept in a horizontal plane. A vertical time varying magnetic field $B=2t$ is switched on at $t=0$ Then the flow of charge per unit time from any section of coil is

asked Mar 21, 2014 by meena.p

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A magnetic flux passing perpendicular to plane of a coil is varying according to the relation. $\phi =3t^2+2t+5$ milliwebers. the emf induced at $t=2 \;sec$ is :

asked Mar 21, 2014 by meena.p

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An aeroplane in which the distance between the tips of using is $50\;m$ is flying horizontally with speed of $360\;km/hr$ over a place where the vertical component of earth's magnetic field is $2.0 \times 10^{-4}\;Weber /m^{2}$ The potential difference between the tips of wings will be

asked Mar 21, 2014 by meena.p

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Calculate the mutual inductance between two coils when a current of 4 A changing to 8 A in 0.5 s in one coil, induces an emf of 50 mV in the other coil.

asked Mar 12, 2014 by balaji.thirumalai

1 answer

Consider a solenoid coil with $N= 10$ turns with radius $12 \times 10^{−2}m$. The solenoid is subjected to a varying magnetic field that changes uniformly from $5 T \rightarrow 2 T$ in an interval of $12 s$. The axis of the solenoid makes an angle of $13 ^{\circ}$ to the magnetic field. If the angle is changed to $67 ^{\circ}$, what would the radius need to be for the emf to remain the same?

asked Mar 12, 2014 by balaji.thirumalai

1 answer

A circular coil of $N=5$ turns with radius $r=1.73 m$ is subjected to a varying magnetic field that changes uniformly from $2.18 T$ to $12.7 T$ in an interval of $180 \text{seconds}$. The axis of the solenoid makes an angle of $27 ^{\circ}$ to the magnetic field. Find the induced emf.

asked Mar 12, 2014 by balaji.thirumalai

1 answer

An aircraft having a wingspan of $20.48\; m$ flies due north at aspeed of $40 ms^{−1}$. If the vertical component of earth’s magneticfield at the place is $2 × 10^{−5}\; T$, Calculate the emf induced betweenthe ends of the wings.

asked Mar 12, 2014 by balaji.thirumalai

1 answer

A circular coil of area $0.04 m^2$, 200 turns and resistance 2 $\Omega$ changes from $0.1 \;Wb \;m^{−2}$ to $0.04 \;Wb\; m^{−2}$ in $0.02 \text{seconds}$. Find the induced emf.

asked Mar 12, 2014 by balaji.thirumalai

1 answer