Select the correct statements regarding dissolved Oxygen and Biochemical Oxygen demand.
A: BOD is inversely related to dissolved oxygen
B: Low dissolved oxygen and high BOD lead to loss of aquatic life.
C: High BOD leads to high dissolved oxygen
D: Both BOD and dissolved oxygen are indicator of health of a water body
E: Both BOD and dissolved oxygen are affected by amount of organic matter in the water body.
Choose the most appropriate answer from the options given below:
1. (A), (B), (C), (E) only 2. (A), (B), (D), (E) only
3. (A), (B), (C), (D) only 4. (B), (C), (D), (E) only

Subtopic:  Water Pollution |
 74%
From NCERT
NEET - 2023
Please attempt this question first.
Hints
Please attempt this question first.

What effect will be observed if sewage in untreated condition is disposed off in freshwater body?
1. BOD and dissolved oxygen will increase. 
2. BOD and dissolved oxygen will decrease.
3. BOD will increase but dissolved oxygen will decrease.
4. BOD will decrease but dissolved oxygen will increase.

 
Subtopic:  Water Pollution |
 77%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.



Given below are two statements: 
Assertion (A): Noise is stressing for human beings.
Reason (R): Chronic exposure to a relatively lower noise level of cities may permanently damage the hearing abilities of humans.
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

 
Subtopic:  Air Pollution |
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.

advertisementadvertisement

Given below are two statements: 
Assertion (A): As the water flows through the marshes of . · Arcata, it gets purified naturally.
Reason (R): Only fungi and bacteria were seeded into 7. this area, which neutralise, absorb and assimilates the pollutants.
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

 
Subtopic:  Water Pollution |
 52%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.

Given below are two statements: 
Assertion (A): During recycling of e-waste in countries like India, China and Pakistan workers are_ 8. exposed to toxic substances present in e-waste.
Reason (R): Over half of e-wastes generated in the developed world are exported to developing countries.
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

 
Subtopic:  Solid Waste Pollution |
 66%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.

Given below are two statements: 
Assertion (A): Problems due to use of chemical fertilisers in agriculture are extremely grave.
Reason (R): Agrochemicals can't be toxic to non-target organisms that are important components of the soil ecosystem
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic:  Agrochemical & Radioactive Waste |
 56%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.

advertisementadvertisement


Given below are two statements: 
Assertion (A): Greenhouse effect heats up earth's surface
Reason (R): Half of incoming solar radiations as well as heat energy released by gases like CO2 and methane cause increase in temperature of earth's surface.
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

 
Subtopic:  Green House Effect & Global Warming |
 65%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.

Given below are two statements: 
Assertion (A): There is increase in melting of Himalayan snow caps and polar ice caps.
Reason (R): Rise in temperature is leading to s1,Jch deleterious changes in the environment.
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

 
Subtopic:  Green House Effect & Global Warming |
 71%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.



Given below are two statements: 
Assertion (A): Forest can be conserved in a sustainable manner.
Reason (R): Forest purifies air and makes it useful to animals.
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

 
Subtopic:  Deforestation |
 59%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.

advertisementadvertisement

Given below are two statements: 
Assertion (A): Depletion of ozone is particularly marked over the Antartic region.
Reason (R): Ozone depletion is occurring widely in the stratosphere due to pollutants like CFCs.
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

 
Subtopic:  Ozone Layer Depletion |
 59%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.