Questions

This is the reason why we see the same side of  the moon always

The size of the pupil of the eye automatically adjusts itself  according to the intensity of light passing through it;if the intensity is more , the size is less, if less, it is more. So in our case the pupil should dilate i.e, increase in size to be able to see in the dark . This switchover takes sometime. But here the entry into the dark room is immediate . So the eye has no time to adjust itself and hence is not able to see at all for a while.

The hertz (Hz) is defined as one cycle per second and is a SI unit of frequency. Here kilohertz is also a unit of frequency of waves and is defined as 1000 cycles per second. Radio waves are measured in kilohertz (KHz).

A place where government records are kept are called Archives.

Indian Cricket team off-spin specialist Ravichandran Ashwin has become the fastest cricketer to take 250 wickets in the Test matches. Ashwin surpassed Australian fast bowler Dennis Keith Lillee to reach the milestone of 250 Test wicket. Thus Ravichandran Ashwin has become the sixth Indian bowler to reach 250 test wickets.