76. In general, wind speed of 105–137 km/h cause
(A) minor or no damage
(B) considerable damage
(C) severe damage
(D) extreme damage
The answer is: (A) minor or no damage ☑
77. Acid rain is mainly caused by emissions of __________ in the atmosphere.
(A) Sulfur Dioxide and Potassium Nitrate
(B) Sulfur and Charcoal
(C) Nitrogen Oxide and Potassium Nitrate
(D) Sulfur Dioxide and Nitrogen Oxide
The answer is: (D) Sulfur Dioxide and Nitrogen Oxide ☑
78. About 50% of the Earth’s crust, including the waters on the Earth and atmosphere, is
(A) Oxygen
(B) Carbon Dioxide
(C) Silicon
(D) Clay
The answer is: (A) Oxygen ☑
79. The fourth state of matter is
(A) Water
(B) Salts
(C) Vapours
(D) Plasma
The answer is: (D) Plasma ☑
80. The device used to convert Alternate Current into Direct Current is called
(A) Anemometer
(B) Battery
(C) Galvanometer
(D) Rectifier
The answer is: (D) Rectifier ☑