Indian army has published the notification for SSC Tech 56 men and SSC Tech 27 women for the course commencing at OTA Chennai from April 2021
A luminous object is placed at a distance of 40 cm from a converging lens of focal length 25 cm. The image obtained on the screen is ?
erect and magnified
erect and smaller
inverted and magnified
inverted and smaller
When a light ray enters into the glass medium from water at an angle of incidence 0°, what would be the angle of refraction?
90°
45°
0°
The ray will not enter at all
Which one of the following phenomena verifies the fact that light travels much faster than sound?
Twinkling of stars in the night sky
Lighting of a matchstick
Thunderstorm
Mirage
Which one of the following combinations of source and screen would produce the sharpest shadow of an opaque object?
A point source and an opaque screen
An extended source and an opaque screen
A point source and a transparent screen
An extended source and a transparent screen
Which one among the following is a non-conventional source of energy?
Petroleum
Coal
Radioactive elements
Solar energy
