The acceleration of an electron of mass m and charge e, moving with uniform speed v at right angles to a magnetic field of flux density B, is give by

Direction of magnetic flux is

In step up transformer, voltage in the secondary increases and power in secondary

The magnetic flux linked with a coil is changed from 1 weber to 0.1 weber in 0.1 sec. the induced e.m.f is:

Laminated core in a transformer is used to reduce

A transformer steps 220 V to 40 voltages. If the secondary turns are 40 and primary turns are:

During one cycle, the direction of flow of alternating current

In a step up transformer the turn ratio is 1:2. A Lechlanche cell (emf = 1.5 V) is connected across the primary. The voltage across the secondary is:

The maximum value of induced emf in a coil rotating in magnetic field does not depend on

The north pole of a long horizontal bar magnet is being brought closer to a vertical conducting plane along the perpendicular direction. The direction of the induced current in the conducting plane will be

The armature of a generator consists of a flat square coil of side 4 cm and 200 turns. The coil rotates in a magnetic field of 0.75T. The angular speed so that a maximum emf of 1.6V is generated is           

An electron moving east is acted on by a magnetic field in the north direction. The force on the electron is:

Two charges are projected in a magnetic field. Their paths after entering field is shown in figure. What type of these charges are?

A wire of length 2 m carries a current of 10 A. What is the force acting on it when it is placed at an angle of 45° to the uniform magnetic field of 0.15 T?

A charged particle of mass m and charge q travels on a circular path of radius r that is perpendicular to a magnetic field B. The frequency taken by the particle to complete one revolution is

The ability of a material to conduct magnetic flux through it.

An electron and a proton with equal momentum enter perpendicularly into a uniform magnetic field, then

Lenz's law gives

According to Flemming’s left-hand rule, the index finger denotes?

When a bar magnet is broken into two pieces, which of the following are true?

When a wire loop is rotated in a magnetic field, the direction of induced emf changes in every

If the supply frequency (f) of a transformer decrease, the effect of frequency on the transformer's secondary output voltage?

An electron and a proton enter a magnetic field perpendicularly. Both have same kinetic energy. Which of the following is true?

A power station generates 600 MW of electrical power which is fed to a transmission line. If the input voltage is 300 KV, then what current would flow in the transmission line?

A circular loop of area 200 cm² lies in x-z plane, then a uniform magnetic field B = (0.3i + 0.4j) is applied on it, find the magnetic flux through the loop:

A coil having 500 square loops each of side 10 cm is placed normal to a magnetic field which increases at a rate of 1T/s. The induced emf in volts is:

An electron is moving in circle of radius r in a uniform magnetic field B. Suddenly the field is reduced to B/2 The radius of the circle now becomes

A loop of radius 1 m is place on a inclined of 60 degree with the magnetic field of 100 T, corresponding flux will be

Eddy currents produced in the core of transformer are responsible for

Steady current I flows through a wire. A circular loop of wire is placed next to the wire. Which of the following will produce an induced current in the loop?

A bar magnet is hung by a string with North Pole faced downward starts oscillating above a horizontal circular coil. Which of the following statement about the induced current is true (viewed from above).

A generator produces a voltage that is given by V=230 sin 314 t volt, where time “t” is in second. The frequency of this voltage is:

A copper ring having a cut such as not to form a complete loop is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet is:

Which quantity is decreased in an ideal step-down transformer?

For an efficient transformer, the hysteresis loop for its core is ___ in size:

Out of following, what is true for a transformer?