The
magnetic force is maximum when the angle between current direction and magnetic
field is…………………..
a) 180
b) 90
c) 0
d) 45
If an object is
placed at principle focus of convex lens the image will be at:
a) di = 2F
b) di < F
c) di < 2F and di <F
d) di =( infinity)
Explanation: When an object is placed at the principal focus of a convex lens, the refracted rays become parallel to each other after passing through the lens. As a result, the image is formed at infinity. This type of image is known as a virtual image.
Therefore, the correct answer is d) di = (infinity).
The molar specific at constant volume for polyatomic gas is:
a) CV =R
b) CV= 2R
c) CV=3R
d) CV=4R
Cathode rays are beam of………………
a) protons
b) electrons
c) neutrons
d) ions
