Question

Assertion :Secondary treatment of sewage is also called biological treatment while primary treatment is called physical treatment. Reason: Primary sewage treatment depends only upon sedimentation properties of materials present in sewage and filtration.

• A. If both assertion and reason are true and reason is the correct explanation of assertion.
• B. If both assertion and reason are true but reason is not the correct explanation of assertion.
• C. If assertion is true but reason is false.
• D. If both assertion and reason are false

Answer 1

The correct option is A If both assertion and reason are true and reason is the correct explanation of assertion.

Primary treatment includes the physical process of screening, comminution, grit removal, and sedimentation. Secondary treatment is typically performed by indigenous, aquatic microorganisms in a managed aerobic habitat; it is biological process.

So, the correct option is 'If both assertion and reason are true and reason is the correct explanation of assertion'