In the relation \(\phi \) = BA cos \(\theta \), \(\theta \) is angle........

SI unit of magnetic flux is

A wire of length 2m moves with a speed of 5m/s perpendicular to a magnetic field of induction 0.1 Wb/m². The e.m.f. induced in the wire is

Choose the quality whose SI unit is not ohm.

Which of the following does not have the dimension of time?

A train is moving with uniform speed from north to south. Will any induced e.m.f. appear across the ends of its axle ? Will the answer be affected if train moves from east to west ?

Name the S.I. units of magnetic flux and magnetic induction.

When is magnetic flux linked with a coil held in a magnetic field zero ?

The induced e.m.f. is sometimes called back e.m.f. Why ?

Why are oscillations of a copper sheet in a magnetic field highly damped ?

Two coils are being moved out of magnetic field- one coil is moved rapidly and the other slowly. In which case is more work done and why?

Give the direction in which the induced current flows in the coil mounted on an insulating stand when a bar magnet is quickly moved along the axis of the coil from one side to the other as shown.

How is the mutual inductance of a pair of coils affected when separation between the coils is increased? The number of turns of each coil is increased? A thin iron sheet is placed between the two coils, other factors remaining the same? Explain your answer in each case.

A rectangular wire frame, shown below, is placed in a uniform magnetic field directed upward and normal to the plane of the paper. The part AB is connected to a spring. The spring is stretched and released when the wire AB has come to the position A’B’ (t = 0). How would the induced emf vary with time? Neglect damping

Show that the rate of change of magnetic flux has the same units as induced e.m.f.

A circular brass loop of radius a and resistance R is placed with its plane perpendicular to a magnetic field, which varies with time as \(B={ B }_{ 0 }sin\omega t.\) Obtain the expression for the induced current in the loop.

Consider Experiment
(a) What would you do to obtain a large deflection of the galvanometer?
(b) How would you demonstrate the presence of an induced current in the absence of a galvanometer?

A solenoid with an iron core and a bulb are connected to a.d.c source. How does the brightness of bulb change when iron core is removed from the solenoid ?

How days the mutual inductance of a pair of coils hange when
(i) distance between the coils is increased
(ii) an iron sheet is placed between the two coils ?

A series LCR circuit with \(R=20\Omega \) , L = 1.5H and \(C=35\mu F\) is connected to a variable frequency 200 V ac supply. When the frequency of the supply equals the natural frequency of the circuit, what is the average power transferred to the circuit in one complete cycle?

A coil of inductance 0.50H and resistance \(100\Omega \) is connected to a 240V, 50 Hz AC supply. 
(a) What is the maximum current in the coil?
(b) What is the time lag between the voltage maximum and the current maximum?

A \(100\mu F\) capacitor in series with a \(40\Omega \) is connected to a 110 V, 60 Hz supply.
(a) What is the maximum current in the circuit?
(b) What is the time lag between the current maximum and the voltage maximum?