Question 1 :
When a rectangular coil is rotated in a uniform magnetic field about an axis passing through its centre and perpendicular to the field, the emf induced in the coil varies:

Question 2 :
Henry, the SI unit of inductance can be written as :

Question 3 :
Assertion (A): Whenever the magnetic flux linked&#160;with a closed coil changes there will be an&#160;induced emf as well as an induced current.<br/>Reason (R): According to Faraday, the induced&#160;emf is inversely proportional to the rate of change&#160;of magnetic flux linked with a coil.<br/>

Question 4 :
Two coils A and B have mutual inductance $2\times 10^{-2}$ henry. If the current in the primary is $i = 5\sin (10\pi t)$ then the maximum value of e.m.f. induced in coil B is:

Question 5 :
In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are&#160;

Question 9 :
When a straight wire is moved up and down rapidly between two poles of a horseshoe magnet then _______ is produced in the wire.

Question 10 :
In a transformer, coefficient of mutual inductance between primary and secondary coil is 0.2 H. When current changes by 5 Na in the primary, then: the induced era in the secondary will be

Question 11 :
When a current of 5 A flows in the primary coil then the flux linked with the secondary coil is 200 weber. The value of coefficient of mutual induction will be

Question 12 :
An airplane with wingspan $50 m$ is flying horizontally with a speed of $360 km hr^{-1}$ over a place where the vertical component of the earth's magnetic field is $2 \times 10^{-2}$. The potential difference between the tips of the wings would be

Question 13 :
If length of a solenoid is increased then what change should be made on no. of turns to keep self inductance constant-<br>

Question 14 :
The magnetic flux linked with a coil satisfies the relation $\phi = 4t^{2} + 6t + 9$ Wb, where t is the time in second. The emf induced in the coil at $t = 2s$ is

Question 15 :
If 'N' is the number of turns in a circular coil then the value of self inductance varies as<br/>

Question 17 :
An emf of $100$ millivolts is induced in a coil when the current in another nearby coil becomes $10\ A$ from zero to $0.1\ sec$. The corfficient of mutual induction between the two coils will be

Question 18 :
A closed circuit consists of a resistor $R$, inductor of inductance $L$and a source of emf $E$are connected in series. If the inductance of the coil is abruptly decreased to$L/4$(by removing its magnetic core), the new current immediately after this moment is : (before decreasing the inductance the circuit is in steady state)

Question 19 :
Assertion: In the phenomenon of mutual induction, self Induction of each of the coil persists. Reason: Self induction arises when strength of current in one coil changes. In mutual induction, current is changing in both the individual coils.

Question 20 :
A long solenoid has $1000\ $turns. When a current of $4\ A$ flows through it, the magnetic flux linked with each turn of the solenoid is $4\times 10^{-3}$Wb. The self-inductance of the solenoid is:

Question 21 :
A very small circular loop of radius $a$ is initially (at $t=0$) coplanar and concentric with a much larger fixed circular loop of radius $b$. A constant current $I$ flows in the larger loop. The smaller loop is rotated with a constant angular speed $\omega $ about the common diameter. The emf induced in the smaller loop as a function of time $t$ is:

Question 22 :
A conducting metal circular-wire-loop of radius r is placed perpendicular to a magnetic field which varies with time as $B =B_0e^{-t/\tau}$, where $B_0$ and $\tau$are constants, at time t = 0. If the resistance of the loop is R then the heat generated in the loop after a long time $(t \rightarrow \infty)$ is<br>

Question 23 :
The uniform magnetic field perpendicular to the plane of a conducting ring of radius $a$ changes at the rate of $\alpha$, then

Question 24 :
Light with energy flux of 18$\mathrm { w } / \mathrm { cm } ^ { 2 }$ falls on a non reflecting surface of area 20$\mathrm { cm } ^ { 2 }$ at normal incidence the momentum delivered in $30$ minutes ise

Question 25 :
A uniform magnetic field exists in region given by $\vec{B}=3\hat{i}+4\hat{j}+5\hat{k}$. A rod of length $5$m is placed along y-axis is moved along x-axis with constant speed $1$m$/$sec. Then induced e.m.f. in the rod will be.

Question 26 :
A flexible wire loop in the shape of a circle has a radius that grows linearly with time. There is a magnetic field perpendicular to the plane of the loop that has a magnitude inversely proportional to the distance from the center of the loop, $B(r)\propto \cfrac{1}{r}$. How does the emf vary with time?

Question 27 :
A circular coil of radius $10\ cm, 500$ turns and resistance $2\Omega$ is placed with its plane perpendicular to the horizontal component of the earth's magnetic field. If is rotated about its vertical diameter through $180^{\circ}m$ in $0.25\ s$. The current induced in the coil is<br>(Horizontal component of the earth's magnetic field at that place is $3.0\times 10^{-5}T)$.

Question 28 :
The magnetic flux $ \phi $linked with a coil depends on time t as $ \phi= at^n $ , where a and n are constants. The emfinduced in the coil is e

Question 30 :
Two identical coaxial circular loops carry a current I each<br/>circulating in the same direction If the loops approach each other, you will observe that<br/>