41. If 3(4-x)≤4x+5, then
(a) x≤1
(b) x≤6
(c) x≥1
(d) x≥6

42. A convex lens of focal length 40 cm is in contact with a concave lens of focal length 25 cm. What is the power of the combination?
(a) -1.5D
(b) +1.5D
(c) +6.5 D
(d) -6.5 D

43.Which of the following substances is a bad conductor of electricity but a good conductor of heat?
(a) Asbestos
(b) Celluloid
(c) Pun Speck
(d) Mica

44. How do most insects respire?
(a) Through skin
(b) Through gills
(c) By lungs
(d) By trachea system

45.If the blood group of a father and a mother are A and O respectively then which one of the following blood group is not possible in their children?
(a) B
(b) AB
(c) O
(d) B, AB or O

46. The volume of a cylinder is 660 cm3. Find its height if its radium is 5 cm.
(a) 8.4 cm
(b) 8.0 cm
(c) 9.4 cm
(d) 9.0 cm

47.Brass is the mixture of:
(a) Tin+Copper
(b) Tin+Zinc
(c) Tin+Copper+Zinc
(d) Zinc+Copper

48. No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be
(a) either plane or convex
(b) plane only
(c) concave
(d) convex only