Q.1.

A magnetic field is made up of flux lines.

Q.2.

Hysteresis is the number of lines of force per unit area in a magnetic field.

Q.3.

A relay is an electromagnetically controlled mechanical device in which electrical contacts are opened or closed by a magnetizing current.

Q.4.

Reluctance in a magnetic circuit is analogous to current in an electrical circuit.

Q.5.

If a conductor is moved back and forth at a constant rate in a constant magnetic field, the voltage in the conductor will reverse polarity.

Q.6.

Materials with a low retentivity do not retain a magnetic field very well.

Q.7.
A magnetic field exists around
Q.8.
For a given wire-wound core, an increase in current through the coil
Q.9.
Which of the following is expected to have the maximum permeability ?
Q.10.
The attraction capacity of electromagnet will increase if the
Q.11.
Unit for quantity of electricity is
Q.12.
The initial permeability of an iron rod is
Q.13.
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.14.
Aturn coil having an axial length ofmm and a radius ofmm 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.15.
The main constituent of permalloy is
Q.16.
Tesla is a unit of
Q.17.
The bar magnet has
Q.18.
The electromagnet hasturns and a current offlows through the coil. If the length of the magnet circuit ismm, what is the magnetic field strength?
Q.19.
If a copper disc is rotated rapidly below a freely suspended magnetic needle, the magnetic needle shall start rotating with a velocity
Q.20.
The unit of relative permeability is
Q.21.
Out of the following statements, concerning an electric field, which statement is not true?
Q.22.
The force between two long parallel conductors is inversely proportional to
Q.23.
Ferrites are a sub-group of
Q.24.
Fleming's left hand rule is used to find
Q.25.
Core of an electromagnet should have
Q.26.
The uniform magnetic field is
Q.27.
Ferrites are materials.
Q.28.
The commonly used material for shielding or screening magnetism is
Q.29.
The ratio of intensity of magnetisation to the magnetisation force is known as
Q.30.
What is the magnitude and the direction of force per 1.length of a pair of conductors of a direct current linecarryingamperes and spacedmm apart ?