21. The leaves of which of the following are used as food for silk worms?
(a) Mulberry tree
(b) Banyan tree
(c) Cotton plant
(d) Betel plant
22. An aquatic respiratory organ of fish is
(a) Gill
(b) Mouth
(c) Lungs
(d) Operculum
23. Which thermometer is used to indicate the lowest temperature?
(a) Clinical thermometer
(b) Resistance thermometer
(c) Alcohol thermometer
(d) Liquid thermometer
24. The metal used in manufacturing steel is
(a) Iron
(b) Tin
(c) Manganese
(d) None of these
25. Who invented X-ray ?
(a) Einstein
(b) Baird
(c) Rutherford
(d) Roentgen
26. The deficiency of vitamin A causes
(a) Beri-beri
(b) Rickets
(c) Night blindness
(d) Scurvy
27. The largest part of the human brain is
(a) Cerebrum
(b) Cerebellum
(c) Medulla oblongata
(d)Mid brain
28. Bacillus Calmette-Guerin (BCG) vaccine is used to produce immunity against
(a) Whooping cough
(b) Tuberculosis
(c) Influenza
(d) Virus fever
29. The blue colour of the clear sky is due to
(a) Scattering
(b) Refraction
(c) Reflection
(d) Diffraction
30. Ornithology is the study of
(a) Birds
(b) Insects
(c) Worms
(d) Cats
31. Which of the following is the best conductor of electricity ?
(a) Mica
(b) Silver
(c) Copper
(d) Zinc
32. Which of the following does not contain minerals ?
(a) Jaggery
(b) Fruits
(c) Vegetables
(d) Milk
33. Which of the following planets has the maximum number of satellites?
(a) Saturn
(b) Jupiter
(c) Earth
(d) Mars
34. The correct sequence of planets in the descending order of their equatorial diameters is
(a) Mars, Pluto, Uranus, Earth
(b) Earth, Mars, Pluto, Uranus
(c) Pluto, Uranus, Mars, Earth
(d) Uranus, Earth, Mars, Pluto