Q.1
A 200 turn coil having an axial length of 30 mm and a radius of 10 mm is pivoted in a magnetic field having a flux density of 0.8 T. If the coil carries a current of 0.5 A, the torque acting on the coil will be
[Hint. Torque = 2BIlNr N-m]
Q.2
The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields
Q.3
The attraction capacity of electromagnet will increase if the
Q.4
Which of the following is expected to have the maximum permeability ?
Q.5
Tesla is a unit of
Q.6
The bar magnet has
Q.7
The electromagnet has 50 turns and a current of 1A flows through the coil. If the length of the magnet circuit is 200 mm, what is the magnetic field strength?
Q.8
The initial permeability of an iron rod is
Q.9
Unit for quantity of electricity is
Q.10
If a copper disc is rotated rapidly below a freely suspended magnetic needle, the magnetic needle shall start rotating with a velocity
Q.11
The main constituent of permalloy is
Q.12
The unit of relative permeability is
Q.13
Core of an electromagnet should have
Q.14
Fleming's left hand rule is used to find
Q.15
Ferrites are a sub-group of
Q.16
The force between two long parallel conductors is inversely proportional to
Q.17
Out of the following statements, concerning an electric field, which statement is not true?
Q.18
The ratio of intensity of magnetisation to the magnetisation force is known as
Q.19
What is the magnitude and the direction of force per 1.1m length of a pair of conductors of a direct current linecarrying 10 amperes and spaced 100 mm apart ?
Q.20
The commonly used material for shielding or screening magnetism is
Q.21
Ferrites are materials.
Q.22
The uniform magnetic field is
Q.23
The use of permanent magnets is. not made in
Q.24
Degaussing is the process of
Q.25
Air gap has_______eluctance as compared to iron or steel path
Q.26
Which of the following is a ferromagnetic material?
Q.27
Susceptibility is positive for
Q.28
Which of the following materials are diamagnetic?
Q.29
A 300 mm long conductor is carrying a current of 10 A and is situated at right angles to a magnetic field having a flux density of 0.8 T ; the force on the conductor will be
Q.30
A material which is slightly repelled by a magnetic field is known as
0 h : 0 m : 1 s