81. Which phenomenon increases Earth’s temperature?
A) Cooling
B) Greenhouse effect
C) Reflection
D) Refraction
Answer: B
82. Which is a natural pollutant?
A) Dust
B) Plastic
C) Oil
D) Metal
Answer: A
83. Which is an anthropogenic pollutant?
A) Volcano ash
B) Industrial waste
C) Dust
D) Sea salt
Answer: B
84. Which is responsible for ozone hole?
A) CFCs
B) CO₂
C) O₂
D) N₂
Answer: A
85. The main cause of global warming is:
A) Deforestation
B) Oxygen
C) Nitrogen
D) Hydrogen
Answer: A
86. Which is a clean fuel?
A) Coal
B) Petrol
C) CNG
D) Diesel
Answer: C
87. Which gas is used in fire extinguishers?
A) CO₂
B) O₂
C) N₂
D) H₂
Answer: A
88. Which sector emits most CO₂?
A) Transport
B) Education
C) Health
D) Sports
Answer: A
89. Which is not biodegradable?
A) Paper
B) Plastic
C) Food
D) Leaves
Answer: B
90. Composting helps in:
A) Waste reduction
B) Pollution increase
C) Soil damage
D) None
Answer: A