12th Class PHYSICS MCQs CHAPTER NO.3 ELECTROMAGNETISM Test No.1

A 0.50 T field over an area of 2 (m²) which lies at an angle of 30^° to the field, the magnetic flux is

The galvanometer in which the coil comes to rest quickly after the current passed through it, is called

CRO when beam of electrons falls on screen; it makes a visible spot because the screen is

A 5 meter wire carrying a current of 2 A is at right angles to the uniform magnetic field of 0.5 weber/(m² The force on the wire is

In a moving coil galvanometer, the deflecting. Torque depends upon

In velocity selector a charged particle will go undeflecting if V is equal to

Magnetic flux will be minimum when

In western type galvanometer, the jeweled bearings are used produced

The brightness of the spot On CRO screen is controlled by

The current passing through a coil of galvanometer is given by

If the current passing through a wire in a magnetic field is halved the magnetic force would become

A charge projected in the direction of magnetic field experiences

Ammeter is a

A high speed graph plotting device is

In galvanometer, the restoring couple of the suspension wire is proportional to the angle of deflection as long as the wire obeys

Magnetic field along the axis of a solenoid with N turns carrying a current I is given by

Which of the, following is most suitable for the core of an electromagnet?

An ammeter only can be used in________ in a circuit

Magnetic flux per unit area perpendicular to magnetic field is called

An ideal ammeter has ________resistance

Sensitivity of galvanometer is given by

The magnetic field outside the solenoid due to current is

When a current carrying conductor is placed in a uniform magnetic field, it experience a force which is given by

A galvanometer is converted into an ammeter by connecting a suitable

In CRO when cathode is .heated by a filament, it emits

The direction of lines of force depends upon the direction of

Total number of lines of magnetic induction passing through any surface placed perpendicular to the field is called:

A long tightly wound cylindrical coil of wire is called

In CRO the grid is at _______potential with respect to cathode

The working of all electrical instruments depends upon

In CRO, beam of electrons is focused by

The relation between current I and the angle of deflection in a moving coil galvanometer is:

The mathematical expression Σ [(B^→). (l^→)] = (µ₀I) is known as

Minimum current required to produce a deflection of one mm on a scale at a distance of 1 meter is

In a galvanometer, the enameled copper wire is wound on

Sensitivity of Galvanometer can he increased by increasing

The galvanometer can be made sensitive if the value of the factor BAN/C is

In galvanometer the coil is situated in the magnetic field such that the plane of the coil is always

Magnetic flux will be maximum when

Two parallel straight wires carrying currents in opposite direction

When charged particle is projected perpendicular to a uniform magnetic field its trajectors is

In SI units, the value of permeability of free space (μ) is

Magnetic force performs

When current passes through a solenoid coil, it behaves like a

Torque necessary to produce unit twist is called

In CRO the x-plates deflect the beam of electrons _________ on screen

Which of the following particle moving in the magnetic field cannot be deflected

Two parallel straight wires carrying currents in same direction

The magnetic force is simply a

The magnetic force experienced by a chai.ge particle is maximum, when charge particle is projected at

CRO is used for displaying the wave form of a given

The Working of a galvanometer depends upon

A magnetic field is always set up due to

Magnetic flux density due to current carrying conductor can be determined by

Which one of the following field is suitable choice for circular trajector of a charged partical

The electron, gun in CRO consists of

The SI unit of magnetic induction is

Charge to mass ratio (e/m) of a proton is_________ that of electron

The beam of electrons in CRO is deflected when they pass through uniform

Magnetic field inside a long solenoid is

One tesla is equal to

The force experienced by a single charge carrier moving with velocity V^→ in a magnetic field of strength B^→ is given by

The magnitude of the deflecting torque on a current carrying coil in

The unit of magnetic flux is

When an electron enters in a perpendicular magnetic field of its motion. then direction of its motion

Cathode ray oscilloscope works by deflecting beam of

SI unit of magnetic flux is

The SI units of magnetic permeability is

One tesla is equal to

The magnetic effect near the current carrying conductor was discovered by

A device used for the detection of current is called

The magnetic force experienced by a charge particle is zero, when charge particle is projected at

The current passing through coil of the galvanometer is

In a straight current carrying conductor, the direction of magnetic field can be found by

The magnetic field in a certain region is given by (B^→) = (40i^{^})-(18j^{^}). How much flux passes a 5.0 cm² area loop in this region if the loop lies hate in the xy-plane

When charged particle enters perpendicular in magnetic field, it moves in

When an electron enters in a magnetic field, right angle to its motion. then the magnitude of velocity will be

In e/m experiment, the path of the electron can be made visible by filling glass tube with

A current carrying conductor experiences maximum magnetic force in a uniform magnetic field when it-is placed

If current is passing through a wire, lines of force near it are

In galvanometer the rectangular coil is made up of

When the coil of the galvanometer is in equilibrium; then the deflecting couple is

The working of galvanometer depends upon torque on a current carrying coil in

A current carrying wire is surround by

The waveform produced by sweep or time base generator in CRO is

If an electron enters the perpendicular magnetic field with a velocity v^→ it will experience a force which is given by F=

The sensitivity of a moving coil galvanometer can be, increased by

The e/m of an electron can be expressed as

Lorentz force is given by

The force Experienced by a charge particle is maximum if it moves

The magnetic field at a point due to a current carrying conductor is directly proportional to

When a charged particle moves through a magnetic field, the effect of the field, changes the particle's

The grid in CRO

Charge to mass ratio of neutron is__________ that of electron

The e/m of an electron moving in a circular path in a magnetic field is given by

Ampere's law can be used to calculate the_______field