# 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

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

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

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

61. The steam engine was invented by

(1) James Watt

(2) James Prescott Joule

(3) New Commen

(4) Isaac Newton

62. Who invented the telephone?

(1) Thomas Alva Edison

(2) Galileo

(3) Alexander Graham Bell

(4) G. Marconi

63. Albert Einstein was a famous

(1) Physician

(2) Chemist

(3) Physicist

(4) Biologist