Question 1 : A thin circular ring of area A is perpendicular to the uniform magnetic field of induction B. A small cut is made in the ring and a galvanometer is connected across the ends such that the total resistance of the circuit is R. When the ring is suddenly squeezed to zero areas, the charge flowing through the galvanometer is 

Question 2 : If a coil of metal wire is kept stationary in a non-uniform magnetic field, then

Question 3 : A coil having $n$ turns and resistance $\mathrm{R}\Omega$ is connected with a galvanometer of resistance $ 4\mathrm{R}\Omega$. This combination is moved in time $\mathrm{t}$ seconds from a magnetic field $\mathrm{W}_{1}$ weber to $\mathrm{W}_{2}$ weber. The induced current in the circuit is:&#160;<br/>

Question 4 : A coil having 100 turns is kept in a uniform magnetic field of induction 0.5 T. If its area changes from 0.3 $m^2$ to 0.1 $m^2$ in 10 s, then the emf induced is ______V.

Question 5 : A straight conductor 0.1 m long moves in a uniform magnetic field ).1T. The velocity of the conductor is 15 m/s and is directed perpendicular to the field. The e.m.f. induced between the two ends of the conductors is. <br>

Question 6 : A 2 m long metallic rod&#160;rotates with an angular frequency of $200 \,rad s^{-1}$ about an axis normal to the rod&#160;passing through its one end. The other end of the rod is in contact with a&#160;circular metallic ring. A constant magnetic field of 0.5 T parallel to the axis exists&#160;everywhere. The emf developed between the centre and the ring is then<br/>

Question 7 : When a voltage source that is inducing voltage into a large number of coils is disconnected, and a switch that is in series with the coils of wire is also opened, a spark is observed to jump across the switch terminals as the switch begins to open up. Identify the cause of this spark?

Question 8 : Assertion : Magnetic flux is a vector quantity<br/>Reason : Value of magnetic flux can be positive,&#160;negative or zero.&#160;<br/>

Question 9 : <div>Two large vertical and parallel metal plates having a separation of 1 cm are connected to a DC voltage source of potential difference X. A proton is released at rest midway between the two plates. It is found to move at 45 to the vertical JUST after release. Then X is nearly</div><div><br></div>

Question 10 : A wire 40 cm long is bent into a rectangular frame 15 cm $&#160;\times&#160; 5 cm $&#160; and placed perpendicular to a field of induction 0.8 $T$ in 0.5 second. The frame is change into a square frame and the filed is increased to&#160;1.4 T. Then e.m.f induced in the frame is

Question 11 : The flux linked with a coil at any instant t is given by&#160; $\phi =10\mathrm{t}^{2}-50\mathrm{t}+250$&#160;&#160;The induced emf at $t = 3 s$ is_____<br/>

Question 13 : The normal drawn to the surface of a conductor makes an angle $\theta$ with the direction of field $\vec{B}$, the flux $\phi$ passing through the area $\vec{A}$ is given by&nbsp;

Question 14 : A coil of N=100 turns carries a current I=5 A and creates a magnetic flux $\varphi=10^{-5}\,Tm^{-2}$ per turn. The value of its inductance L will be&nbsp;

Question 15 : Two identical coaxial coils P and Q carrying equal amount of current in the same direction are brought nearer. The current in:

Question 16 : The radius of a coil decreases steadily at the rate of $ 10^{2} $ m/s. A constant and uniform magnetic field&#160;of induction $ 10^{3} Wb/m^2 $ acts perpendicular to the plane of the coil. The radius of the coil when the induced&#160;e.m.f. in the coil is 1 $\mu $&#160;V, is

Question 17 : If magnetic flux through area $20\ m^2$ at point $P$&nbsp;in magnetic field is $50$ Weber then magnetic induction at point $P$&nbsp;is :

Question 18 : A solenoid of inductance $L$ carrying a certain current&#160;is linked with a total magnetic flux $\phi $. Now it is&#160;connected to a condenser with which it shares half&#160;of its initial energy. The total flux now linked with&#160;the solenoid is:<br/>

Question 19 : A rectangular coil of $100$ turns and size $0.1m \times 0.05$m is placed perpendicular to a magnetic field of $0.1$T. If the field drops to $0.05$T in $0.05$ second, the magnitude of the e.m.f. induced in the coil is.<br/>

Question 20 : A coil of area $10{cm}^{2}$ and $10$ turns is in magnetic field directed perpendicular to the plane and changing at a rate of ${10}^{8}$ $gauss/s$. The resistance of coil is $20\Omega$. The current in the coil will be

Question 21 : A flat square loop with a side a = 20 cm is placed in a magnatic field B = $ ( a +&nbsp;\beta t^2) $&nbsp;Where $&nbsp;\alpha $ and $ \beta $ are constants and the plane of the loop is at right to B. Find the induced emf generated in the loop at time t = 5

Question 22 : A conducting circular loop is placed in a uniform magnetic field B$=$ 40 mT with its plane perpendicular to the field. If the radius of the loop starts shrinking at a constant rate of 2 mms$^{-1}$, then the induced emf in the loop at an instant when its radius is 1.0 cm is

Question 23 : A thin circular ring of area $A$ is perpendicular to uniform magnetic field of induction $B$. A small cut is made in the ring and a galvanometer is connected across the ends such that the total resistance of circuit is $R$. When the ring is suddenly squeezed to zero area, the charge flowing through the galvanometer is

Question 24 : A wire 88 cm long bent into a circular loop is placed&nbsp;perpendicular to the magnetic field of flux density 2.5 Wb $m^{-2}$. Within 0.5 s, the loop is changed into a square and&nbsp;flux density is increased to 3.0 Wb $m^{-2}$. The value of e.m.f.&nbsp;induced is :

Question 25 : A thin circular ring of area A is held perpendicular to a uniform magnetic field of induction B. A small cut is made in the ring and a galvanometer is connected across the ends such that the total resistance of the circuit is R. When the ring is suddenly squeezed to zero area, the charge flowing through the galvanometer is<br>

Question 26 : To induce an e.m.f. in a coil, the linking magnetic flux

Question 27 : $N$ turns are tightly wound to form a spiral plane of outer radius $a$. If the magnetic induction $B= B_0 &#160; \sin &#160;\omega t$ varies perpendicular to the plane of spiral then find the emf induced in the spiral.

Question 28 : The magnetic flux of $ 50\&#160; \mu Wb$ passing through a 200 turns coil is reversed in $ 2 \times 10^{-3} $ seconds. The average e.m.f induced in the coill in volts is

Question 29 : A coil of circular cross-section having $1000$ turns and $4 cm^2$ face area is placed with its axis parallel to a magnetic field which decreases by $10^{-2} Wb- m^{-2}$ in $0.01 s$. The e.m.f. induced in the coil is:&#160;<br/>

Question 30 : What will be the magnitude of e.m.f. induced in a 200 turns coil with cross section area 0.16$m^{2}$?&#160;The magnetic field through the coil changes from 0.10 Wb $m^{-2}$ to&#160;<span>0.30 Wb, at a uniform rate over a period of 0.05 s:</span>

Question 31 : A loop of wire enclosing an area $S$ is placed in a region where the magnetic field is perpendicular to the plane. The magnetic field $\vec { B } $ varies with the time according to the expression $B={B}_{0}{e}^{-at}$ where $a$ is some constant emf in the loop as a function of time. Calculate the induced emf?

Question 32 : Magnetic flux through a circuit of resistance $20\Omega&nbsp;$ is changed from 20 Wb to 40 Wb in 5 ms. Charge passed through the circuit during this time is

Question 33 : The phenomenon of producing an emf in a circuit whenever the magnetic flux linked with a coil changes is ________.

Question 34 : A copper ring is moved towards the north pole of a bar magnet. Then

Question 35 : A square coil $10^{-2}m^2$ area is placed perpendicular to a uniform magnetic field of intensity $10^3 \,Wb / m^2.$. The magnetic flux&#160;through the coil is

Question 36 : A circular coil of radius $8$cm and $20$ turns rotates about its vertical diameter with an angular speed of 50 rad $s^{-1}$ in a uniform horizontal magnetic field of $8\times 10^{-2}T.$ The maximum emf induced in the coil is nearly

Question 37 : A coil having an area of $2\ m^{2}$ is placed in a magnetic field which changes from $1\ Weber/ m^{2}$ to $4\ Weber/ m^{2}$ in $2$ seconds. The e.m.f. induced in the coil will be

Question 38 : <span>Complete the following sentence:</span><div>The current is induced in a closed circuit only if there is _________.</div>

Question 40 : According to Faraday's law, the total charge induced in a conductor that is moved in a magnetic field depends upon:

Question 41 : The magnetic flux through a circuit of resistance R changes by an amount $\Delta\phi$ in a time $\Delta t$. Then the total quantity of electric charge Q that passes any point in the circuit during the time $\Delta t$ is represented by :

Question 42 : A rectangular coil is rotated in a uniform magnetic field about an axis passing through its centre and perpendicular to the direction of the field, then the induced voltage in the coil is directly proportional to the:

Question 44 : A magnetic field $B=2t+4{t}^{2}$ (where $t=$ time) is applied perpendicular to the plane of a circular wire of radius $r$ and resistance $R$. If all the units are in $SI$, the electric charge that flows through the circular wire during $t=0s$ to $t=2s$ is:

Question 45 : An e.m.f. of 5 volt is produced by a self inductance, when the current changes at a steady rate from 3 A to 2 A in 1 millisecond. The value of self inductance is

Question 46 : A circular loop of radius $2\ cm$, is placed in a time varying magnetic field with rate of $2T/sec$. Then induced electric field in this loop will be:

Question 47 : Whenever there is a change in the magnetic flux linked with a closed circuit, an emf and a current are induced in the circuit. This statement is referred to as:

Question 48 : <p class="wysiwyg-text-align-left"><span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium">If area vector&#160;$\vec{A}=3\hat{i}+2\hat{j}+5\hat{k}\ m^{2}$ </span></span><span class="wysiwyg-font-size-xx-small"><span class="wysiwyg-font-size-xx-small">&#160;</span></span><span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium">flux density&#160;</span></span><span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium">vector $\vec{B}=5\hat{i}+10\hat{j}+6\hat{k}(Wb/m^{2})$</span></span><span class="wysiwyg-font-size-medium"><span class="wysiwyg-font-size-medium">. The magnetic&#160;</span></span><span>flux linked with the coil is</span></p>

Question 49 : Two concentrated co-planar coils of equal turn have radii $10$ cm and $30$ cm respectively. The same current is passed into in both the coils in the same direction. Now the direction of currents is reversed in one coil then,&#160;the ratio of magnetic flux at their common centre is:

Question 50 : A coil of area $A_0$ is lying in such a magnetic field whose value changes from $B_0$ to $4B_0$&#160;<div>in $t$ seconds. The induced emf in the coil will be :</div>