GENERAL SCIENCE
SCIENCE MCQs FOR COMPETITIVE EXAMS
SHORT QUESTIONS WITH ANSWERS
Question No. 1
It is not advisable to sleep under trees during the night.
Answer
During the night the plants release carbon dioxide (CO2) which is a poisonous gas
and injurious to health. That is why it is not advisable to sleep under trees at
night.
Question No. 2
A Rainbow is produced in the sky after rainfall and sunlight.
Answer
After the rain, many droplets of water travel into the atmosphere. When sun rays
fall on these droplets, dispersion of water occurs and droplets act as a prism and
produce a spectrum of seven colors. That’s why a rainbow is seen in the sky after
rain.
Question No. 3
Why do some people snore?
Answer
Some people snore during their sleep because the breathing action produces
sound. This is so because the pharynx or the windpipe offers resistance to the air
taken in or expelled.
, Question No. 4
Why do we sometimes sleepwalk?
Answer
Sleepwalk is a sort of disorder of sleep in which a person starts walking during his
sleep. The sleeper walks and performs complex activities automatically without
regaining consciousness.
Question No. 5
Why do the stars twinkle?
Answer
The light from the stars travels through different layers of space of varying
densities. Therefore, the light rays deviate from their original path. Further, these
layers are not stationary but keep on moving. This leads to the twinkling of stars.
Question No. 6
It is difficult to drown in the Dead Sea. Why?
Answer
The water of the Dead Sea has a salt content of 27%. Therefore, its density is
much greater than that of ordinary seawater and it also offers a greater upthrust.
Hence, the body weighs less than an equal volume of Dead Sea water and is thus,
able to float
Question No. 7
Every fourth year has 366 days. Explain.
Answer
One revolution of the earth around the sun takes 356 days and 6 hours. But we
consider a year as consisting of only 365 days and ignore 6 hours. In four years,
SCIENCE MCQs FOR COMPETITIVE EXAMS
SHORT QUESTIONS WITH ANSWERS
Question No. 1
It is not advisable to sleep under trees during the night.
Answer
During the night the plants release carbon dioxide (CO2) which is a poisonous gas
and injurious to health. That is why it is not advisable to sleep under trees at
night.
Question No. 2
A Rainbow is produced in the sky after rainfall and sunlight.
Answer
After the rain, many droplets of water travel into the atmosphere. When sun rays
fall on these droplets, dispersion of water occurs and droplets act as a prism and
produce a spectrum of seven colors. That’s why a rainbow is seen in the sky after
rain.
Question No. 3
Why do some people snore?
Answer
Some people snore during their sleep because the breathing action produces
sound. This is so because the pharynx or the windpipe offers resistance to the air
taken in or expelled.
, Question No. 4
Why do we sometimes sleepwalk?
Answer
Sleepwalk is a sort of disorder of sleep in which a person starts walking during his
sleep. The sleeper walks and performs complex activities automatically without
regaining consciousness.
Question No. 5
Why do the stars twinkle?
Answer
The light from the stars travels through different layers of space of varying
densities. Therefore, the light rays deviate from their original path. Further, these
layers are not stationary but keep on moving. This leads to the twinkling of stars.
Question No. 6
It is difficult to drown in the Dead Sea. Why?
Answer
The water of the Dead Sea has a salt content of 27%. Therefore, its density is
much greater than that of ordinary seawater and it also offers a greater upthrust.
Hence, the body weighs less than an equal volume of Dead Sea water and is thus,
able to float
Question No. 7
Every fourth year has 366 days. Explain.
Answer
One revolution of the earth around the sun takes 356 days and 6 hours. But we
consider a year as consisting of only 365 days and ignore 6 hours. In four years,
