Q31. What is it called when an atom of an element has more than one mass number?
(A) Isotope
(B) Isomer
(C) Isotone
(D) Isobar
(A) Isotope
Q32. Litmus acid base indicator is obtained from-
(A) By virus
(B) From bacteria
(C) From lichen
(D) None of these
(C) From lichen
Q33. A rubber balloon filled with hydrogen bursts when it goes up in the air because-
(A) Air pressure decreases
(B) Air pressure increases
(C) The weight of hydrogen increases
(D) The pressure of hydrogen decreases
(A) Air pressure decreases
Q34. From where is iodine obtained?
(A) Laminaria
(B) Gracilaria
(C) Odogonium
(D) Spirogyra
(A) Laminaria
Q35. When a rock is brought from the surface of the moon to the earth, then
(A) Both weight and mass will change
(B) Its mass will change
(C) Neither mass nor weight will change
(D) Its weight will change but not its mass
(D) Its weight will change but not its mass
Q36. Gold can be dissolved in-
(A) Hydrochloric acid
(B) Sulphuric acid
(C) Nitric acid
(D) A mixture of three parts hydrochloric acid and one part nitric acid
(D) A mixture of three parts hydrochloric acid and one part nitric acid
Q37. Which one of the following animals is a mammal?
(A) Platypus
(B) Great Indian Sarung
(C) Dhanesh
(D) Alligator
(A) Platypus
Q38. Which of the following is used in thermometers?
(A) Zinc
(B) Lead
(C) Mercury
(D) Tin
(C) Mercury
Q39. Which of the following is an oviparous mammal?
(A) Kangaroo
(B) Monotreme
(C) Bats
(D) Blue whale
(B) Monotreme
Q40. The speed of sound is maximum in-
(A) In air
(B) In vacuum
(C) In water
(D) In steel
(D) In steel