Home
Current Affairs January 2024

What is the correct answer?

4

A permanent magnet does not exert a force on

A. an unmagnetized iron bar

B. a magnetized iron bar

C. a moving electric charge

D. a stationary electric charge

Correct Answer :

D. a stationary electric charge


Related Questions

What is the correct answer?

4

A magnetic field is

A. The current flow through space around a permanent magnet

B. The force set up when current flows through a conductor

C. The force that drives current through a resistor

D. The force between the plates of a charged capacitor

What is the correct answer?

4

Who discovered the most important electrical effects which is the magnetic effect?

A. Hans Christian Oersted

B. Sir Charles Wheatstone

C. Georg Ohm

D. James Clerk Maxwell

What is the correct answer?

4

The reluctance of a magnetic circuit is not dependent on which of the following?

A. Number of turns of coil

B. Magnetomotive force

C. Flux density in the circuit

D. Current in the coil

What is the correct answer?

4

Two similar polesa each 1Wba placed 1 m apart in air will experience a repulsive force of

A. 63000 N

B. 63 × 10^-3 N

C. 8 × 10^12 N

D. 796 kN

What is the correct answer?

4

Lenz' law states that the direction of the induced emf and hence current

A. Is determined by the rate of current flux

B. Is found by the right hand rule

C. Is found by the left hand rule

D. Always opposes the cause producing it

What is the correct answer?

4

The greater percentage of materials is _________.

A. diamagnetic

B. paramagnetic

C. ferromagnetic

D. non-magnetic

What is the correct answer?

4

Flux density is measured in

A. Tesia

B. Weber

C. Ampere- turn

D. Maxwell

What is the correct answer?

4

What is the other name for dielectric strength?

A. Breakdown voltage

B. Electric intensity

C. Potential gradient

D. Dielectric constant

What is the correct answer?

4

One oersted (Oe) is equivalent to _____ Gb/cm.

A.

B.

What is the correct answer?

4

The magnetic field of a magnetized iron bar when strongly heated

A. Becomes weaker

B. Becomes stronger

C. Reverses in direction

D. is unchanged

What is the correct answer?

4

Germanium atom has ______ protons and ______ electrons.

A. 32, 32

B. 32, 42

C. 42, 32

D. 34, 34

What is the correct answer?

4

What is another name for relative permittivity?

A. Dielectric strength

B. Electric intensity

C. Potential gradient

D. Dielectric constant

What is the correct answer?

4

A length of wire has a resistance of 10 ohms. What is the resistance of a wire of the same material three times as long and twice the cross-sectional area?

A. 30 ohms

B. 20 ohms

C. 15 ohms

D. 7 ohms

What is the correct answer?

4

The B-H curve of ________ is not a straight line.

A. air

B. wood

C. silicon steel

D. soft iron

What is the correct answer?

4

A magnetic material losses its ferromagnetic properties at a point called

A. Curie temperature

B. Inferred absolute temperature

C. Room temperature

D. Absolute temperature

What is the correct answer?

4

Electrons at the outer shell are called

A. Outer shell electrons

B. Inner shell electrons

C. Semiconductor electrons

D. Valence electrons

What is the correct answer?

4

The space outside the magnet where its pole have a force of attraction or repulsion on a magnetic pole is called

A. Magnetic field

B. Electric field

C. Electromagnetic field

D. Free Space Field

What is the correct answer?

4

The permeability of permalloy is

A. Very much greater than permeability of air

B. Slightly greater than permeability of air

C. Slightly less than permeability of air

D. Equal to the permeability of air

What is the correct answer?

4

When the relative permeability of a material is slightly less than 1a it is called _____ material.

A. diamagnetic

B. ferromagnetic

C. paramagnetic

D. non-magnetic

What is the correct answer?

4

One of the common application of an air- cored choke.

A. Radio frequency

B. Audio frequency

C. Power supply

D. Power transformer

What is the correct answer?

4

If the value of 0 a conductor is 1/234 per oCa then the value of 18is

A. 1/218 per oC

B. 1/252 peroC

C. 1/272 per oC

D. 1/273 per oC

What is the correct answer?

4

The core of a transformer heats up when its primary is fed from an ac source because of

A. permeability

B. ferromagnetism

C. reluctance of core

D. hysteresis loss

What is the correct answer?

4

The simplest type of atom to exist is the ______ atom.

A. Helium

B. Hydrogen

C. Boron

D. Oxygen

What is the correct answer?

4

Whenever a flux inking a coil or current changesa an emf is induced in it. This is known as

A. Joule's Law

B. Coulomb's Law

C. Faraday's first law of electromagnetic induction

D. Faraday's second law of electromagnetic induction

What is the correct answer?

4

It is the reciprocal of reluctance and implies the case of readiness with which magnetic flux is developed.

A. R esistance

B. Conductance

C. Permeance

D. I nductance

What is the correct answer?

4

The net electrical charge in an isolated system remains constant. This is known as

A. Law of conservation of charge

B. Coulomb's first law

C. Coulomb's second law

D. Law of conservation of energy

What is the correct answer?

4

Why is it that the magnitude of magnetomotive force required for air gap is much greater than that required for iron part of a magnetic circuit?

A. Because air is a gas

B. Because air has the highest relative permeability

C. Because air is a conductor of magnetic flux

D. Because air has the lowest relative permeability

What is the correct answer?

4

Which of the following is a diamagnetic material?

A. Aluminum

B. Silver

C. Air

D. Cobalt

What is the correct answer?

4

Who discovered that a current-carrying conductor would move when placed in a magnetic field?

A. Michael Faraday

B. Andre Ampere

C. Hans Christian Oersted

D. Gustav Robert Kirchhoff

What is the correct answer?

4

Which of the following materials has the least hysteresis loop area?

A. soft iron

B. silicon steel

C. hard steel

D. wrought iron