Electromagnetic Induction

In a step-down transformer, the output current _________.

The Lenz's law refers to induced ________.

Power losses in a transformer can be minimized:

A loop of 5 turns of wire is placed in uniform magnetic field of 0.5 T, then area of loop shrinks at a constant rate of 10 m²/s, the emf induced is:

In a practical transformer mutual induction between primary and secondary coils takes place. In such transformer what can be deduced about the power.

In transformer, there is no _ connection between the two coils but they are linked?

A copper hoop is held ina vertical east-west plane in a uniform magnetic field whose field lines run along the north-south direction. The largest induced emf is produced when the hoop is.

The unit of ∆Φ/∆t can be written as?

One meter long copper rod is moving with speed 20 m/sec in the magnetic field of strength 0.6 tesla. What is the value of induced emf?

The quantity ∆φ/∆t has the same units as that of?

The expression for the emf produced by A.C generator is?

Working principal of magnetic levitation train is according to?

The induced emf produced in the coil is sometimes called as?

In principle, the transformer consists of two coils of copper, electrically insulated from each other, wound on the same?

In an ideal transformer:

Electric generators and transformers are based on the principles of:

In an AC generator the emf will be maximum when factor sinωt is equal to:

The induced current flow in such a direction so as to oppose the cause that produces it. The statement is:

In an ideal transformer, if the primary voltage is doubled and the turns ratio remains the same, what happens to the secondary current?

If a loop moves toward a stationary magnet, the induced current will:

A charged particle is moving in a circular orbit of radius 6 cm with a uniform speed of 3x106 m/s under the action of a uniform magnetic field 2x10-4 Wb/m² at right angles to the plane of the orbit. The charge-to-mass ratio of the particle is:

A charged particle moves through a magnetic field directed perpendicular to its direction of motion. Which of the following quantities of the particle will not change?

A coil has 2000 turns and an area of 70cm2. The magnetic field perpendicular to the plane of the coil is 0.3 Wb/m² and takes 0.1 sec to rotate through 180˚. The value of the induced e.m.f. will be:

A metal rod PQ (carrying current from P to Q) is placed perpendicular to the infinite long wire carrying current iI0. If this arrangement lies in a horizontal plane; then the rod PQ will rotate:

Four charges A, B, C, D are shown here, moving with equal speeds in a uniform magnetic field. Which charge experiences the maximum force?

A solenoid is cut into two halves. Magnetic induction due to same current in each half will be:

An electron and a proton enter a magnetic field with equal velocities which one of them experiences more force:

A conductor of length 1m carrying current of 1A is placed parallel to a magnetic field of 1 Gauss. The magnetic force acting on the conductor is:

Which one of the following is not present in AC generator?

Sl unit of magnetic induction is _.

Unit of relative permeability is _.

For which angle between area and magnetic field, the flux is maximum?

A loop of radius 1 m is placed on an incline of 60 with a magnetic field of 100 T. The corresponding flux will be:

In the given diagram, the directions of the induced currents through the coils, when the magnet moves toward the right, are

AC generator converts _ energy:

When coil is rotated in magnetic field, the current produced is:

Transformer can convert _

When a bar magnet is broken from middle, the broken pieces will have:

The motional EMF depends upon

Who introduced the law of electromagnetic induction

According to Faraday's law, EMF induced in circuit depends on _.

A transformer is based on the theory of _.

Henry is the unit of _.

Motional EMF can be produced with _.

The attraction capacity of an electromagnet will increase if the _.

Harmonics in transformer result in _.

According to Faraday's law, EMF stands for _.

Electric motor converts _.

The turns ratio of transformer is 10. It means that _.

In a circuit, there is a current of 5 A which is changed such that the current falls to zero in 0.1 sec. If an average e.m.f. of 200 volts is induced, the self-inductance of the circuit will be:

A circuit in which there is a current of 5 A is changed so that the current falls to zero in 0.1s. If an average e.m.f of 200 volts is induced, what is the self-inductance of the circuit?

The current measuring part of the ammeter consists of several low resistors connected _.

The directions of the magnetic field as given by Fleming’s rule for the solenoid along:

An electron enters a magnetic field at an angle of less than 90 degrees with magnetic field. Which of the following paths is followed by an electron?

If a stationary bar magnet is placed near a coil so that maximum lines of force pass through the coil, the galvanometer shows:

Magnetic flux is maximum when the angle between the magnetic field and vector area is:

A₃-cm length of wire is moved at right angles across a uniform magnetic field with a speed of 2.0 m/s. If the flux density is 5.0 tesla, what is the magnitude of the induced e.m.f?

A force that is experienced in a magnetic field depends on:

Due to the magnetic force, a positively charged particle executes uniform circular motion within a uniform magnetic field ‘B’. If the charge is ‘q’ and the radius of its path is r, which of the expressions gives the magnitude of the particle’s linear momentum:

How fast an H+ ion should move in a magnetic field 2.5x10-3 T such that magnetic force equals its weight?

The current measuring part of the ammeter consists of a number of low resistors connected _.

If an electron passes through the axis of the solenoid the movement will be:

The Curie point shows a relationship between:

In the given diagram, the directions of the induced currents through the coils, when the magnet moves toward the right, are:

A uniform magnetic field B exists in the +ve x direction. A proton (q =+e) shoots through the field in the +ve y direction with the speed v. Calculate v.

In an experiment, a conductor of length 1.0 m is placed perpendicular to an external magnetic field. The given graph shows how the force on the conductor varies as the current through the conductor changes. The magnitude of the magnetic field applied in this experiment will be:

A long solenoid is connected to a galvanometer and a bar magnet is passed perpendicularly through it with uniform speed. Which graph best represents the variation of the galvanometer deflection 0 with time?

In the given figure, a current-carrying conductor is placed in a magnetic field. The direction of the magnetic field will be:

The property of bending of light around obstacles and spreading of light wanes into geometrical shadow of an obstacle is known as:

Find the radius of an orbit of an electron moving at a rate of 2.0 x 107 m/s in a uniform magnetic field of 1.20 x 10-3 T.

The property of bending of light around obstacles and spreading of light wanes into a geometrical shadow of an obstacle is known as:

Fluorescence is the property of absorbing radiant energy of _frequency and re-emitting energy of _ frequency in the visible region of the electromagnetic spectrum.

A nucleus consists of nucleons comprising of protons and neutrons. A proton has a positive charge equal to _ and has a mass of _.

The emission of electrons from a metal surface when exposed to light of suitable frequency is known as:

Find the radius of an orbit of an electron moving at a rate of 2.0 x 10² m/s in a uniform magnetic field of 1.20 x 10 ̄³ T.

Which derived unit below is equivalent to the SI unit for magnetic field strength, the tesla, T?

AC generator converts _ energy.

In an AC generator, AC reverses its direction _ times per second.

When the coil is rotated in the magnetic field, the current produced is:

Eddy currents flow in:

Transformer can convert:

When a bar magnet is broken from the middle, the broken pieces will have:

The magnetic field inside a long solenoid is:

The emf induced in a circuit according to Faraday's law depends on the:

Tesla is a unit of _ per unit area.

The magnetic flux is a _ quantity.

The magnetic field, B, produced in a solenoid depends on:

The cyclotron frequency of an electron projected with velocity perpendicular to a magnetic field B is given by:

The motional E.M.F depends upon:

An electron is moving along the axis of a solenoid carrying a current. Which of the following is a correct statement about the magnetic force acting on the electron?

An electron is projected horizontally from south to north in a uniform horizontal magnetic field acting from west to east. The direction along which it will be deflected is:

An electron and a proton enter a magnetic field with equal velocities. Which one of them experiences more force?

A current-carrying solenoid is cut into a ratio of 1:3 such that both are independently connected with the same source of current. Now if the magnetic field of the first part is “BA” while the second part respectively is “BB” then what is true?

A metallic circular ring is suspended by a string and is kept in a vertical plane. When a magnet is approached towards the ring, then it will:

A conductor of length 1m carrying a current of 1A is placed parallel to a magnetic field of 1 Gauss. The magnetic force acting on the conductor is:

The diagram shows a wire, carrying a current ‘I’, placed between the poles of a magnet. In which direction does the force on the wire act?

A long straight current-carrying conductor has current directed from bottom to top when held vertically. What will be the direction of magnetic field lines when observed from below the conductor?

A solenoid is cut into two halves. Magnetic induction due to the same current in each half will be:

Magnetic Resonance Imaging (MRI) is used to identify the image of:

Due to the current in a straight conductor the difference between magnetic field lines:

A solenoid 15 cm long has 300 turns of wire. A current of 5 A flows through it. What is the magnitude of the magnetic field inside the solenoid?

The diagram shows a wire, carrying a current 'I', placed between the poles of a magnet. In which direction does the force on the wire act?

Two long parallel wires Wire 1 and Wire 2 repel each other as shown in the figure. What could be the reasons?

If the number of turns of a solenoid circular coil is doubled, but the current in the coil and radius of the coil remain the same, then what will be the magnetic flux density produced by the coil?

The electron gun in a cathode ray oscilloscope contains:

Which of the following is the proper way to study the sinusoidal waveform of the voltage?

The voltage that is applied across X-plates is provided by a circuit called:

Two long straight parallel wires held vertically have equal but opposite currents as shown in the figure. Which of the following effects will be observed?

A 10 cm long solenoid has 100 turns. What will be the magnetic field inside it along its axis if one-microampere current is passed through it?

The diagram shows a small magnet hanging on a thread near the end of a solenoid carrying a steady current ‘I’. What happens to the magnet as the iron core is inserted into the solenoid?

Force on the current carrying conductor per unit length is given by:

Magnetic force on a charged particle is:

Who introduced the laws of electromagnetic induction?

An AC generator converts:

The magnetic force between two wires is inversely proportional to the _.

According to Faraday's law, EMF induced in the circuit depends on:

A transformer is based on the theory of:

The flux is the region where the magnetic field _.

Henry is the unit of:

A solenoid bent into a circle is called _.

Magnetic flux is a scalar product of _.

Cosθ=Φ/_.

Motional emf can be produced with:

The attraction capacity of an electromagnet will increase if the:

When currents are moving in the same direction in two conductors, the force will be:

Non-inductive resistances are used in _.

Find the force due to a current of 5 A passing through the element of length 2 cm and flux density of 12 Tesla.

A time-varying magnetic field creates an electric field, this is called _.

A charged particle is moving on a circular path with velocity v in a uniform magnetic field B. If the velocity of the charged particle is doubled and the strength of the magnetic field is halved, then the radius becomes _.

Lorentz force in the electric and magnetic field is:

If a charged particle enters a region where electric and magnetic fields are parallel to its motion, it will:

e/m = _

Harmonics in the transformer result in _.

When a charged particle enters in a strong magnetic field, its kinetic energy _.

According to Faraday's law, EMF stands for:

The attraction capacity of the electromagnet will increase if the:

Lamination of the transformer core is made of:

Power transfer from primary to secondary is through flux linkage, so the primary and secondary coils should be wound in such a way that flux coupling between them is _.

Which one of the following is not present in the AC generator?

An electric motor converts:

The turns ratio of the transformer is 10. It means that _.

The unit of relative permeability is:

If the number of loops is increased, then according to Faraday's law _ will increase.

A strong magnetic field is applied on a stationary electron, then the electron _.

Lenz's law provides information about the direction of _.

In a step-up transformer, _.

A loop of radius 1 m is placed on an incline of 60 degrees with a magnetic field of 100 T, corresponding flux will be _.

Electron charge in accelerating motion will produce _.

If the number of flux passing through a coil per unit time is doubled then the motion emf _.

If the velocity of a charged particle and magnetic field are at a fixed angle (not 90⁰), then the path will be _.

"The direction of the induced current is always so as to oppose the change that causes the current", is _.

If a charged particle moves through a magnetic field perpendicular to it, _.

The magnetic field along the axis of a solenoid with 'n' turns per unit length carrying current 'I' is given by:

For a step-down transformer, Ns _ Np.

If a charged particle is at rest but we are seeing it from a train then we observe _.

A charge of 1 μC is moving antiparallel to magnetic lines of force, then the magnetic force acting on charge is:

If magnetic field vector is B = (i + 5j + 2k ) and area vector is (6i - 2j +2k) then flux related to this is:

The magnetic field is parallel to a surface, then the magnetic flux through the surface is _.

Time-varying magnetic field creates an electric field, this is called _.

A metal rod of length 4 m, velocity 5 m/s, and magnetic field 0.5 T, induced emf is:

In an A.C. generator, an increase in the number of turns in the coil does which of the following?

A circular loop of area 0.05 m² rotates in a uniform magnetic field of 0.2 T. If the loop rotates about its diameter which is perpendicular to the magnetic field, find the flux linked with the loop when its plane is parallel to the field:

If velocity of charged particle and magnetic field are at a fix angle not 90 then path will be

The magnetic flux (ø) linked with a coil is related to the number of turns (N) of the coil as:

Faraday law states that the rate of change of magnetic flux is equal to

A solenoid 15.0 cm long has 300 turns of wire, and a current of 5 A flows through it. The magnitude of magnetic field inside the solenoid is:

Current carrying loop behaves like a

The secondary turns of which of the following transformers is always kept closed for _ transformer.

If magnetic field is given by B= (2i + 3j -8k) and a loop of area 10 sq.m is placed in field in y-z plane, the maximum flux will be:

The voltage turn ratio of step down transformer is:

Faraday's law explains how electric field will interact with:

What is the radius of circular path, if particle has mass m and charge q?

Two α-particles have the ratio of their velocities as 3 : 2 on entering the field. If they move in different circular paths, then the ratio of the radii of their paths is:

If magnetic field is doubled then magnetic energy density becomes

The coupling coefficient of perfectly coupled coil is

Anelectric power is transmitted over long distance through conducting wire at high voltage and low current because

If a proton, alpha particle and photon moving with the same velocity enter in uniform magnetic field, then which particle will deflect more?

If a charged particle enters in a region where electric and magnetic field are parallel to its motion, then it will:

Magnetic flux is scalar product of

If the direction of the field and area vector is opposite then field is

Emf produced in generator is

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

If we make the magnetic field stronger, the value of induced current is

A transformer has negative voltage regulation when its load power factor is

A square loop of side 4 meters is placed in a magnetic field of 10 T and the surface of the loop is making an angle with the field of 60˚. What will be the flux?

Unit of relative permeability is

The attraction capacity of electromagnet will increase if the

Lamination of the transformer core is made of

For ideal step up transformer Ps_Pp.

Can we see magnetic flux lines?

The transformer laminations are insulated from each other by?

The primary and secondary powers of a transformer are 200W and 100 W respectively, the efficiency of a transformer is:

Work done by the magnetic force on a charged particle in presence of a perpendicular magnetic field is?

An a.c. generator consists of a coil of 50 turns and an area of 2.5 m² rotating at an angular speed of 60 rad s-1 in a uniform magnetic field of 0.3 T between two fixed pole pieces. What is the flux through the coil, when the current is zero?

In step up transformer?

A square coil of side length 2 mm is placed in the x-y plane and in uniform magnetic field 0.1 T. Find total flux through the coil?

Force on a moving charge in a uniform magnetic field will be maximum when angle between v and B is?

The principle of transformer is?

A beam of an ion with velocity 2*10^5 m/s enters normally into a magnetic field of 0.04 T. The specific charge of the ion is 5*10^7 C/kg. The radius of the circle is _.

In step down transformer _ is decreased in secondary coils.

Alternating Current Generators use _.

A charge of 2C is travelling parallel to a magnetic field of 4T with 20 m/s. Calculate the net force on it.

Magnetic flux is given by the _.

Magnetic field is very strong where field lines are

Energy stored in an inductor is

If the magnetic field is parallel to a surface, then the magnetic flux through the surface is _.

If a current wire of 2 A and length 5m enters perpendicular to magnetic field of 10T. Calculate the force experienced by it

F = e(vxB) is valid for:

Henry is unit of

SI unit of inductance is

A circular loop of area 0.05 m² rotates in a uniform magnetic field of 0.2 T. If the loop rotates about its diameter which is perpendicular to the magnetic field, find the flux linked with the loop when its plane is normal to the field.

Currents changing with time will produce _ field.

Energy stored inside the inductor is given by _.

When a charged particle enters the magnetic field perpendicular to the velocity of charge, the followed path is _.

For given applied voltage, what will happen if we increase frequency of the applied voltage?

What is the formula for magnetic flux?

Magnetic flux is a _ product.

Magnetic flux is the dot product of magnetic induction and

An electric generator converts _ to _ energy

The strength of the magnetic field is called _.

The insulation between sheets of the transformer core is to get small.

The SI unit of magnetic induction is _.

According to Faraday's Law, emf induced in circuit depends on:

For which angle between area and magnetic field, flux is maximum

A transformer is used to light 100 W 25 volt lamp from 250 Volt ac mains. The current in the main cable is 0.5 A. Calculate the efficiency of the transformer

A charged particle is moving in a cyclotron, what effect on the radius of path of this charged particle will occur when the frequency of the ratio frequency field is doubled?

A circular loop of radius 2 m placed having area in the direction of magnetic field of 100 T, flux will be

For an efficient step down transformer:

A charged particle enters parallel in a strong magnetic field, its K.E?

According to Faraday law EMF stands for:

What is the strength of the magnetic field known as?

The magnetic force between two wires which are having current in opposite direction will:

Which of the following losses in a transformer is zero even at full load?

Find the "Lorentz force" of a charge 2.5C having an electric field of 5 units and magnetic field of 7.25 units with a velocity 1.5m/s.

If the direction of "current" is upward pointed by the "thumb" and the "magnetic field" is north side, then the force will be?

1 Tesla is equal to:

An ideal step down transformer is connected to main supply of 240V. It is desired to operate one 30W lamp of voltage 12V. What is the current in the primary coil?

In order to enhance magnetic flux, the primary and secondary coils of the transformer are wound on?

For a metal rod of length L moving with speed V perpendicular to the magnetic field, the motional EMF at its end is:

An electric power is transmitted over a long distance through conducting wire at high voltage and low current because:

The core of a transformer is made up of:

Find the force due to a current element of length 2cm and flux density of 12 tesla. The current through the element is 5A.

The open-circuit test in a transformer is used to measure:

The magnetic force is simply a:

Mutual induction happens in:

A cable 4km long and of total resistance 1 ohm carries electric current from a generator producing 100kW at 10,000 Volts. The current in amperes in the cable is:

Sensitivity of galvanometer is defined as

One proton beam enters in a magnetic field of 10-4 T normally with specific charge 1011 C/kg and velocity of 107 m/s. What will be the radius of circle?

Transformation ratio of transformer is given by:

For a coil self inductance is L and current is I then flux passing through it is:

In a step-up transformer, _ is increased in the secondary coils.

When currents are moving in the same direction in two conductors, then the force will be:

A 100-turn coil of area 0.1 m² rotates at half a revolution per second. It is placed in a uniform magnetic field of 0.01 T perpendicular to the axis of rotation of the coil. Calculate the maximum voltage generated in the coil?

The magnetic flux (Φ) linked with a coil is related to the number of turns (N) of the coil as:

A steady current passing through a conductor produces:

Voltage in secondary winding is to current in the secondary coil.

When a charge passes through a region undeflected then with Fe = Fm.

If the number of flux passing through a coil per unit time is doubled then the motion emf?

Mutual inductance has a practical role in the performance of?

Magnetic induction is also called?

A monoenergetic electron beam with an electron speed of 5.20 x 106 m/s is subject to a magnetic field of 1.30 x 10-4 T normal to the beam velocity. What is the radius of the circle traced by the beam, given e/m for electron equals 1.76 x 1011 C/kg.

The direction of induced current is always so as to oppose the change which causes the current. This is:

_ field is a region where a charge experiences a force.

Find the maximum force of the conductor having length 60 cm, current 2.75 A, and flux density of 9 units.

Calculate the maximum emf when the velocity is 10 m/s, the length is 3 m, and the magnetic field density is 5 T:

If magnetic field vector is B= (i + 2j +k ) and area vector is (2i + j + k) then flux related to this is:

Electric charge in uniform motion produces:

Step down transformer has _ turns in secondary coil:

Faraday law states that the rate of change of magnetic flux is equal to:

Whenever the magnetic flux linked with an electric circuit changes, an emf is induced in the circuit. This is called:

Magnetic flux density is a:

When Ns>Np then transformer is:

Power transformers have maximum efficiency at

e/m =

Harmonics in transformer result in

The coupling coefficient of perfectly coupled coil is:

What happens to the flux if applied magnetic field is doubled on the same surface?

The principle of a direct current generator is based on:

When north pole of bar magnet moves towards a conducting loop, induced current flows in

Electric field generated due to induction is:

Unit of magnetic flux density is _.

The flux is the region where magnetic field _.

Lenz's law is in accordance with conservation of:

Magnetic force between two wires is proportional to _.

What is the angular frequency during the circular motion?

The turns ratio of transformer is 10, It means that:

Magnetic field density outside the solenoid is:

The magnetic field density outside the solenoid is _.

A real transformer does not change the _.

In a step-down transformer, the _ is decreased in secondary coils.

An electron is moving along the line of force in magnetic field B with velocity u, then the maximum force acting on the charge is given by _.

A rectangular loop of dimension 3 cm by 5 cm is placed perpendicular to a uniform magnetic field of 0.1 T, find the magnetic flux through the loop.

Electric generator converts _ to _ energy.

Is it possible to visualize magnetic flux lines?

A circular loop of radius 2 m placed having an area in the direction of the magnetic field of 100 T, the flux will be?

How can a magnetic field be produced?

The direction of magnetic flux can be found by:

In F = ILB sin θ, θ is the angle between:

How do Eddy Currents flow in a conductor?

Tesla is the unit of:

The value of permeability of free space is:

The magnetic flux of the Earth is:

To convert a galvanometer into voltmeter, the galvanometer is connected with a resistor having _ resistance in _ combination.

A transformer transforms:

The unit of magnetic flux density is:

The magnetic field inside a solenoid is:

Find the turn ratio if Vs / Vp = 2.

Moving charges have:

A step-up transformer increases:

Magnetic flux density is _ per unit area.