1401. Pure gold is :

A. 17 carat
B. 20 carat
C. 24 carat *
D. 36 carat

1402. The sky is blue in colour because of :

A. The Moisture present in the air
B. The way that air molecules or dust particles scatter light *
C. Combination of various lights producing blue colour
D. All the above

1403. Acid rain contains high levels of :

A. Oxalic acid
B. Acetic acid
C. Sulphuric and nitric acids *
D. Carbolic acid

1404. Which gas is used in the preparation of soft drinks ?

A. Carbon dioxide *
B. Oxygen
C. Nitrogen
D. Halogens

1405. How many teeth adults have ?

A. 22
B. 26
C. 32 *
D. 28

1406. Water has maximum density at :

A. 0 degree centigrade
B. 4 degree centigrade *
C. 3 degree centigrade
D. 5 degree centigrade

1407. Who invented the thermometer ?

A. Galileo *
B. Franklin
C. Edison
D. Bell

1408. What was the name of the world’s first human test-tube baby?

A. Louisa *
B. Sarah
C. Martha
D. Heather

1409. Who developed the first blood bank and a system for storing blood plasma ?

A. Lee deforest
B. Charles Drew *
C. Robert Dennard
D. Joseph Dart

1410. Heat from the sun is received by the earth through :

A. Conduction
B. Convection
C. Radiation *
D. None of these