# General Knowledge Practice MCQs Set 12 for IAS 2020

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57. A number consists of two digits whose sum is 8. If 8 is subtracted from the number, the digits interchange their places. The number is

(1) 44

(2) 35

(3) 62

(4) 33

Answer: 4

58. A horse is tied to a peg hammered at one of the corners of a rectangular grass field of 40 m by 24 m by a rope 14 m long. Over how much area of the field can the horse graze?

(1) 154 m2

(2) 308 m2

(3) 240 m2

(4) 480 m2

Answer: 1

59. The sides of a triangle are in the ratio 3 : 5 : 7 and its perimeter is 30 cm. The length of the greatest side of the triangle in cm is

(1) 6

(2) 10

(3) 14

(4) 16

Answer: 3

60. The radius of a right circular cone is 3 cm and its height are 4 cm. The curved surface of the cone will be

(1) 12 sq. cm

(2) 15 sq. cm

(3) 18 sq. cm

(4) 21 sq. cm

Answer: 2

61. The steam engine was invented by

(1) James Watt

(2) James Prescott Joule

(3) New Commen

(4) Isaac Newton

Answer: 1

62. Who invented the telephone?

(1) Thomas Alva Edison

(2) Galileo

(3) Alexander Graham Bell

(4) G. Marconi

Answer: 3

63. Albert Einstein was a famous

(1) Physician

(2) Chemist

(3) Physicist

(4) Biologist

Answer: 3