Selected MCQ

Current Question
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 1
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 2
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.
Related Question 3
Assertion: Diamonds are used in cutting tools. Reason: Diamond is very hard.
  • 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:
Diamond’s extreme hardness makes it suitable for cutting tools.
Related Question 4
Assertion: A rainbow is seen when sunlight passes through raindrops. Reason: Raindrops refract, reflect, and disperse light.
  • 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:
Rainbow formation is due to refraction, reflection, and dispersion in raindrops.
Related Question 5
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.