Physics

Magnetism and Electromagnetism

1,019 Questions

This hub provides practice questions on magnetism and electromagnetism. It covers magnetic flux density, electromagnets, magnetic lines of force, and electromagnetic induction. These physics concepts frequently appear in technical and non-technical competitive exams.

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Magnetism and Electromagnetism Questions

Multiple choice physics electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

What did Orested do in the experiment ?

  1. Placed a compass near an electromagnet and observed its deflection

  2. Placed a compass near a magnet and observed the deflection of compass needle

  3. Placed a compass near a current carrying wire and observed the deflection of compass needle

  4. Placed a compass near an electrolyte and observed the deflection of compass needle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hans Christian Oersted. Hans Christian Oersted began a new scientific epoch when he discovered that electricity and magnetism are linked. He showed by experiment that an electric current flowing through a wire could move a nearby magnet.Oersted's experiment that when an electric current is passed through a conducting wire, a magnetic field is produced around it. The presence of magnetic field at a point around a current carrying wire can be detected with the help of a compass needle

Multiple choice physics electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

The amount of deflection of the magnetic needle in a galvanoscope depends on:

  1. The amount of current passing through the insulated copper wire that is wound over it

  2. Magnetic strength of the magnetic needle

  3. Number of turns of the coil

  4. All the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The deflection in galvanometer is the defined by 

$\tau=NBIA$
The N is number of turns of coils.
B is magnetic strenght of magnetic needles 
I is The amount of current passing through the insulated copper wire that is wound over it
A is area of coil contact with magnetic field.

Multiple choice physics electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

What did Oersted observe while performing the experiment ?

  1. The compass needle placed near an electromagnet deflected

  2. The compass needle kept near an electrolyte deflected

  3. The compass needle kept near a wire carrying electric current deflected when the current was switched ON and OFF.

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Oersted observed while performing the experiment when he passed a current through a wire which caused a nearby magnetic compass needle to move.When current switched off then needle comes to their original position

Multiple choice physics electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

What did Orested discover from his experiment ?

  1. Heating effect of electric current

  2. Magnetic effect of electric current

  3. Chemical effect of electric current

  4. Physical effect of electric current
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the experiment of Oersted's he passed electric current through a wire,which caused a nearby magnetic field so that compass needle move.That shows that magnetic effect of eclectic current.

Multiple choice

What are the strongest magnets called?

  1. Rare earth magnet

  2. Neodymium

  3. Both

  4. Neither
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Neodymium magnets are a type of rare earth magnet, and they are currently the strongest type of permanent magnet available. Since both terms describe the same high-strength category, C is the correct choice.

Multiple choice

Magnets only come in one strength.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Magnets come in a wide variety of strengths depending on their material, size, and composition. Therefore, the statement that they only come in one strength is false.

Multiple choice physics observing space: telescopes maxwell's equations the nature of light introduction to electromagnetic waves

Electromagnetic wave is deflected by

  1. Electric field

  2. Magnetic field

  3. Both ( 1 ) & ( 2 )

  4. Neither electric field nor magnetic field
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

EM waves are formed by electric and magnetic fields but are not deflected by them, and also they can be deflected by gravitational field....

 Light (electromagnetic wave) has an electric and a magnetic field and should thus deflect a compass needle during daytime.

Visible light - Being an Electromagnetic wave is reflected by glass (take mirror).

For highly intense X-Rays & gamma rays, take that the mirror is stronger such that it could resist for at least 30 seconds.

hence, light wave neither electric field nor magnetic field

Multiple choice physics observing space: telescopes maxwell's equations the nature of light introduction to electromagnetic waves

Choose the correct answer from the alternatives given.


Which of the following has/have zero average value in a plane electromagnetic wave?

  1. Both magnetic and electric fields

  2. electric field only

  3. Magnetic field only

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A. Both magnetic and electric field.


Because both electric and magnetic field oscillate as sine and cosine wave, which over one period, average value is zero.