Question 3 :
A coil of insulated wire is connected to a battery. If it is taken to galvanometer, its pointer is deflected, because<br/>

Question 4 :
A metal ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The magnet falls with an acceleration:

Question 6 :
If a magnet is plugged into a coil, then the magnitude of induced emf does not depend upon:

Question 11 :
If the current in the toroidal solenoid increases uniformly from zero to $$6.0A$$ in $$3.0\mu s$$. Self inductance of the toroidal solenoid is $$40\mu H$$. The magnitude of self induced emf is :

Question 12 :
A metal rod moves at a constant velocity in a direction perpendicular to its length. A constant uniform magnetic field exists in space in a direction perpendicular to the rod as well its velocity. Select correct statements (s) from the following<br>

Question 13 :
The area of a circular coil of $$2000$$ turns is $$70cm^2$$. The coil is kept normal to the field of $$0.3W/m^2$$ and rotated through $$180^{\circ} $$. The emf in volts generated in $$1sec$$ will be :

Question 14 :
Assertion: A magnet induces irregular currents in a metal sheet moving past it. Reason: Eddy currents are usually in circular pattern.

Question 15 :
Read the following statements and answer whether the given statement is true or false.Eddy current involves loss of energy in the form of heat.<br/>

Question 16 :
A wheel with 10 metallic spokes each 0.5 m long rotated with a speed of 120 rpm in a plane normal to the horizontal component of earth's magnetic field $$B_h$$ at a place. If $$B_h$$ = 0.4 G at the place. What is the induced emf between the axle and the rim of the wheel? (1 G = $$10^4$$ T)

Question 17 :
A conducting loop rotated with constant anguler velocity $$\omega$$ about its fixed diameter in a&#160; uniform magnetic field, whose direction is perpendicular to that fixed diameter.

Question 18 :
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 19 :
An ac generator consists of a coil of 200 turns, 100 cm in diameter. If the coil rotates at 500 rpm in a magnetic field of 0.25T, then the maximum induced emf

Question 20 :
Two solenoids have identical geometrical construction but one is made of thick wire and the other of thin wire. Which of the following quantities are different for the two solenoids?

Question 21 :
A fan operates at 200 V(dc) consuming 1000 W when running at full speed. Its internal wiring has resistance $$1 \omega $$. When the fan runs at full speed, its speed become constant. This is because the torque due to magnetic field inside the fan is balanced by the torque due to air resistance on the blades of the fan and torque due to friction between the fixed part and the shaft of the fan. The electrical power going into the fan is spent (i) in the internal resistance as heat, call it $$P_1$$(ii) in doing work against internal friction and air resistance producing heat, sound, etc. Call it $$P_2$$. When the coil of fan rotates,an emf is also induced in the coil. This opposes the external emf applied to send the current into the fan. This emf is called back emf, call it e. Answer the following question when the fan is running at full speed.<br><br>The value of power $$P_2$$ is<br>

Question 22 :
Find the inductance of a solenoid of length $$l_0$$, made of Cu windings of mass $$m$$. The winding resistance is equal to $$R$$. The diameter of solenoid &lt;&lt; $$l$$. $$\rho_0$$ is resistivity of Cu and $$\rho$$ is density of the Cu.

Question 23 :
A Rowland ring of mean radius $$15cm$$ has $$3500$$ turns of wire wound on a ferromagnetic core of relative permeability $$800$$. What is the magnetic field $$B$$ in the core for a magnetising current of $$1.2A$$ ?

Question 24 :
The magnitude of the earth's magnetic field at the north pole is $${B}_{0}$$. A horizontal conductor of length $$l$$ moves with a velocity $$v$$. The direction of $$v$$ is perpendicular to the conductor. The induced emf is

Question 25 :
The magnetic flux $$\phi$$ linked with a conducting coil depends on time as $$\phi=4{t}^{n}+6$$, where $$n$$ is a positive constant. The induced emf in the coil is $$e$$.