A bar magnet is divided into two pieces, which of the following statement is correct?
two new magnets are created
the magnetic field of each separate piece becomes stronger
the electric field is created
the bar magnet is demagnetized
Correct answer is A
When it is cut into two, the two cut pieces will have their own north and south poles.
The reason for laminating the soft iron core of a transformer is to?
reduce eddy current.
reduce magnetic flux.
increase the magnetic flux.
reduce its efficiency.
Correct answer is A
Laminated iron core means insulating layers glued compact. Now the cores are laminated to reduce Eddy current.
The process of energy production in the sun is?
nuclear fission
nuclear fusion
electron collision
radioactive decay
Correct answer is B
The process of energy production in the sun is generally by nuclear fusion of hydrogen nuclei, the reaction of which takes place at a tremendous high temperature.
200Ω
50Ω
100π
25πΩ
Correct answer is A
Given;
L = 2H
F = 50π H2
XL = ?
XL = 2πfL = 2π x 50λ x 2
= 200Ω
An astronomical telescope is said to be in normal adjustment when the?
eye is accommodated
focal length of an object lens is longer than that of eye piece
final image is at the near point of eye
final image is at infinity
Correct answer is D
A normal arrangement is an arrangement where the principal focus of objective coincides with the eyepiece so that the final image is at infinity