Selected MCQ

Current Question
Assertion: Ice floats on water. Reason: Ice is less dense than liquid water.
  • A. Both are true and the reason correctly explains the assertion
  • B. Both are true but the reason does not explain the assertion
  • C. Assertion is true but reason is false
  • D. Assertion is false but reason is true
Correct Answer: A
Explanation:
Lower density makes ice float on water.
Related Question 1
Assertion: Steam can burn more severely than boiling water. Reason: Steam contains latent heat in addition to heat at 100°C.
  • A. Both are true and the reason correctly explains the assertion
  • B. Both are true but the reason does not explain the assertion
  • C. Assertion is true but reason is false
  • D. Assertion is false but reason is true
Correct Answer: A
Explanation:
Steam releases extra latent heat on condensation, making burns more severe.
Related Question 2
Assertion: Salt is added to icy roads in winter. Reason: Salt lowers the freezing point of water.
  • A. Both are true and the reason correctly explains the assertion
  • B. Both are true but the reason does not explain the assertion
  • C. Assertion is true but reason is false
  • D. Assertion is false but reason is true
Correct Answer: A
Explanation:
Salt helps melt ice by lowering water’s freezing point.
Related Question 3
Assertion: Glass windows crack when heated unevenly. Reason: Uneven heating causes unequal expansion in different parts of the glass.
  • A. Both are true and the reason correctly explains the assertion
  • B. Both are true but the reason does not explain the assertion
  • C. Assertion is true but reason is false
  • D. Assertion is false but reason is true
Correct Answer: A
Explanation:
Unequal expansion creates stress in the glass and causes cracking.
Related Question 4
Assertion: A compass needle points north-south. Reason: Earth acts like a giant magnet.
  • A. Both are true and the reason correctly explains the assertion
  • B. Both are true but the reason does not explain the assertion
  • C. Assertion is true but reason is false
  • D. Assertion is false but reason is true
Correct Answer: A
Explanation:
The compass aligns with Earth’s magnetic field.
Related Question 5
Assertion: The Earth revolves around the Sun. Reason: This revolution, along with axial tilt, causes seasons.
  • A. Both are true and the reason correctly explains the assertion
  • B. Both are true but the reason does not explain the assertion
  • C. Assertion is true but reason is false
  • D. Assertion is false but reason is true
Correct Answer: B
Explanation:
The reason states an effect of revolution, not why Earth revolves.