Showing 31–40 of 419 questions
Q.31
Medium
General Science
Which of the following vitamins helps in calcium absorption?
A
Vitamin A
B
Vitamin B
C
Vitamin D
D
Vitamin E
Correct Answer:
C. Vitamin D
Explanation:
Vitamin D helps in the absorption of calcium from the intestines, essential for bone health and development.
Q.32
Medium
General Science
What is the process by which solids directly convert to gases without becoming liquids?
A
Melting
B
Evaporation
C
Sublimation
D
Condensation
Correct Answer:
C. Sublimation
Explanation:
Sublimation is the process where a solid directly converts to a gas. Dry ice (solid CO₂) is a common example.
Q.33
Medium
General Science
Which blood group is considered a universal donor?
Explanation:
O- blood type is the universal donor as it lacks A, B, and Rh antigens on red blood cells.
Q.34
Medium
General Science
What is the chemical formula for sulfuric acid?
A
H₂SO₃
B
H₂SO₄
C
HSO₄
D
H₃SO₄
Explanation:
Sulfuric acid is H₂SO₄, one of the most important industrial chemicals with numerous applications.
Q.35
Medium
General Science
In the context of Newton's Laws of Motion, which law states that action and reaction are equal and opposite?
A
First Law
B
Second Law
C
Third Law
D
Fourth Law
Correct Answer:
C. Third Law
Explanation:
Newton's Third Law states that for every action, there is an equal and opposite reaction.
Q.36
Hard
General Science
Which of the following is an example of a heterogeneous mixture?
A
Salt solution
B
Sugar solution
C
Sand and iron filings
D
Alcohol and water
Correct Answer:
C. Sand and iron filings
Explanation:
Sand and iron filings form a heterogeneous mixture as their components remain visibly distinct and can be easily separated.
Q.37
Hard
General Science
What is the Doppler effect primarily related to?
A
Change in density
B
Change in frequency or wavelength of waves due to relative motion
C
Change in amplitude
D
Change in intensity
Correct Answer:
B. Change in frequency or wavelength of waves due to relative motion
Explanation:
The Doppler effect describes the change in frequency or wavelength of waves when the source or observer moves relative to each other.
Q.38
Hard
General Science
Which type of lens is used to correct myopia (short-sightedness)?
A
Convex lens
B
Concave lens
C
Bifocal lens
D
Cylindrical lens
Correct Answer:
B. Concave lens
Explanation:
Concave lenses are used to correct myopia by diverging light rays to focus them correctly on the retina.
Q.39
Hard
General Science
Which of the following statements about entropy is correct?
A
Entropy always decreases in an isolated system
B
Entropy is a measure of disorder and always increases in an isolated system
C
Entropy has no relation to the direction of chemical reactions
D
Entropy can be negative in physical systems
Correct Answer:
B. Entropy is a measure of disorder and always increases in an isolated system
Explanation:
According to the Second Law of Thermodynamics, entropy (disorder) of an isolated system always increases over time.
Q.40
Easy
General Science
Which gas is primarily responsible for the greenhouse effect?
A
Nitrogen
B
Carbon dioxide
C
Oxygen
D
Argon
Correct Answer:
B. Carbon dioxide
Explanation:
Carbon dioxide (CO₂) is the primary greenhouse gas responsible for global warming. It traps heat in the atmosphere.