## A coil of wire is arranged with its plane perpendicular to a uniform magnetic field o flux density B. when the radius of the coil increases from r1 to r2 in…

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# Electromagnetic Induction

## For electroplating we use_________________?

For electroplating we use_________________? A. A D.C source B. an A.C source C. any source D. all of the above

## The only difference between construction of D.C generator and A.C generator is that…

The only difference between construction of D.C generator and A.C generator is that of_______________? A. carbon brushes B. coilC. commutator D. magnetic field

## If the secondary coil has Ns turns and the primary Np turns the relation between secondary and…

If the secondary coil has Ns turns and the primary Np turns the relation between secondary and primary voltages is given by_____________? A. Vs/Vp = Np/NsB. Vs/Vp = Ns/Np C. Vp/Vs = Ns/Np D. Vp/Vs = Np/Ns…

## A metal rod of 25 cm length is moving at a speed of 0.5/sec in direction perpendicular to 0.25T…

A metal rod of 25 cm length is moving at a speed of 0.5/sec in direction perpendicular to 0.25T magnetic field. Emf produced in the rod is_____________? A. 0 volt B. 3.125 volt C. 31.25 voltD. 0.03125 volt…

## The self-inductance of a solenoid is increased when a soft iron core is inserted into it. This is…

The self-inductance of a solenoid is increased when a soft iron core is inserted into it. This is because the soft iron core_______________? A. Decreases the resistance of the solenoid B. Reduces the effect of eddy currentC.…

## An aeroplane of wingspan 10m flies from the equator towards the North Pole. The wings are…

An aeroplane of wingspan 10m flies from the equator towards the North Pole. The wings are perpendicular to the vertical component of the earths magnetic field (B = 4×10-5T). At maximum speed an emf of 96mV is induced across the wing tips.…

## Non inductive resistances are used in decreasing______________?

Non inductive resistances are used in decreasing______________? A. Mutual inductanceB. Self inductance C. Magnetic fields D. Heating effect

## Which one of the following devices does not function like an electric motor ?

Which one of the following devices does not function like an electric motor ? A. Galvanometer B. Ammeter C. VoltmeterD. Transformer

## For long distance transmission the transformer used is_____________?

For long distance transmission the transformer used is_____________? A. Step down B. Input voltage and output voltage remain sameC. Step up D. Amplifier is used

## Lagging of changes in the magnetization of a substance behind changes in the magnetic field as the…

Lagging of changes in the magnetization of a substance behind changes in the magnetic field as the magnetic field is varied is known as magnetic_____________? A. Retaintivity B. Permeability C. FluxD. Hysteresis…