21000+ Important MCQs for UPSC

1) A cavern is an underground chamber formed by

2) When two similar sources vibrate with slightly different frequencies , a regular rise and fall occurs in the loudness of tone. This phenomenon is known as

3) What region is also referred as the Garden of southern India ?

4) Proteins differ from one another because

5) Consider the following statements:
1.Diabetes insipidus causes diuresis, i.e., urine is passed out several times more than in a normal person.
2.A person with diabetes insipidus suffers from very low or no output of vasopressin.
3.Such diabetic patients drink large quantity of water.
4.Vasopressin is secreted by hypothalamus and stored in posterior pituitary. Which of the above statements is/are correct?

6) In cold countries alcohol is preferred to mercury as a thermometric liquid because

7) O2 released in the process of photosynthesis comes from

8) The two isotopes of uranium, 235U and 238U have
1. equal number of protons
2. equal number of neutrons
3. 92 protons each 
Which of the above statements is/are correct?

9) Such fish that are found in rivers in Australia and Africa where water is too foul to support life with the usual gills are
1.dipnoins
2.lung fishes
3.sturgeons
4.guppies

10) By what process is heat transmitted from the filament of an evacuated electric bulb to the glass?