Free Environment and Atmosphere MCQs with Answers

131. Electrostatic precipitator is used to control?

• A. Air pollution
• B. Water pollution
• C. Solid waste
• D. Noise pollution

Explanation: An electrostatic precipitator removes dust and fine particulate matter from industrial exhaust by electrically charging particles and collecting them on oppositely charged plates. It therefore controls air pollution rather than water, solid-waste or noise pollution.

132. The atmospheric air is held to the Earth by?

• A. gravity
• B. winds
• C. clouds
• D. rotation of the Earth

Explanation: Earth’s gravity attracts the gases in the atmosphere and keeps them from escaping into space. Winds only move air within the atmosphere; they do not hold it to Earth.

133. Pluviometer measures ___________?

• A. Wind
• B. Strength of Plywood
• C. Rainfall
• D. None of these

Explanation: A pluviometer, also called a rain gauge, collects and measures the amount of rainfall over a period. It does not measure wind speed or strength of materials.

134. Heat transfer horizontally within the atmosphere is called?

• A. Conduction
• B. Convection
• C. Absorption
• D. Advection

Explanation: Advection is the horizontal movement of heat or another atmospheric property by moving air. Convection mainly describes vertical transfer caused by rising warm air and sinking cool air.

135. Which one of the following wavelengths of light is most effective in photosynthesis?

• A. Blue
• B. Green
• C. Orange
• D. Yellow

Explanation: Chlorophyll absorbs blue and red light most efficiently for photosynthesis, while green light is largely reflected. Among the listed choices, blue is therefore the best answer.

136. A state of stress caused by concern for the earth's environment is called?

• A. Eco-anxiety
• B. Eco-fear
• C. Eco-depression
• D. Eco-alarm

Explanation: Eco-anxiety is persistent worry or distress about environmental damage and climate change. The other terms are not the established name for this condition.

137. The cause for the Tsunami, as deduced by the seismologists, is?

• A. gravitational pull of the moon
• B. low pressure trough in the ocean
• C. deformation of sea floor and vertical displacement of water
• D. sudden change in the monsoon wind

Explanation: Most tsunamis begin when an undersea earthquake suddenly deforms the seabed and vertically displaces the overlying water. Tides, pressure troughs and monsoon winds do not normally produce tsunami waves.

138. Which ocean is called "Ring of Fire"?

• A. Indian Ocean
• B. Pacific Ocean
• C. Atlantic Ocean
• D. Antarctic Ocean

Explanation: The Pacific Ocean is surrounded by a zone of frequent earthquakes and volcanic eruptions called the Pacific Ring of Fire. The other oceans do not have an equivalent continuous belt of activity.

139. Which of the following is called smallest, shallowest and coldest ocean of the world?

• A. Pacific Ocean
• B. Indian Ocean
• C. Arctic Ocean
• D. None of the above

Explanation: The Arctic Ocean is the smallest, shallowest, and coldest of the five major oceans. Its location around the North Pole keeps much of it covered by sea ice.

140. Which of the following ocean is the least polluted ocean of the world?

• A. Arctic Ocean
• B. Indian Ocean
• C. South Pacific
• D. None of the above

Explanation: The South Pacific is commonly cited in general-knowledge sources as among the least polluted ocean regions because it is remote from major industrial and population centres. Pollution rankings can vary depending on whether plastics, chemicals, or overall contamination is measured.