Q41. Due to what do sound waves produce echo?
(A) Refraction
(B) Reflection
(C) Diffraction
(D) None of these
(B) Reflection
Q42. What is fuse wire made of?
(A) Alloy of nickel and chromium
(B) Alloy of tin and copper
(C) Alloy of tin and aluminium
(D) Alloy of tin and lead
(D) Alloy of tin and lead
Q43. The normal temperature of the human body according to the Kelvin scale is-
(A) 310
(B) 300
(C) 290
(D) 320
(A) 310
Q44. Who is the national aquatic animal of India?
(A) Alligator
(B) Crocodile
(C) Gangetic Dolphin
(D) Soft-shelled turtle
(C) Gangetic Dolphin
Q45. If both parents have blood group AB, then the possible blood groups of their children would be-
(A) A, B and AB
(B) A और B
(C) A, B, AB and 0
(D) A, B और O
(A) A, B and AB
Q46. Which of the following is not soluble in water?
(A) Zinc sulphate
(B) Sodium
(C) Lead sulphate
(D) Potassium
(C) Lead sulphate
Q47. Which is the main protein found in milk?
(A) Casein
(B) Globin
(C) Albumin
(D) Globulized
(A) Casein
Q48. What is the transmission of heat through molecular movement called?
(A) Ripening
(B) Conduction
(C) Convection
(D) Radiation
(C) Convection
Q49. Which of the following is used as a semiconductor in transistors?
(A) Copper
(B) Germanium
(C) Graphite
(D) Silver
(B) Germanium
Q50. Vitamin A is also known as.
(A) Riboflavin
(B) Retinol
(C) Calciferol
(D) Thyamit
(B) Retinol