Q.21
Easy
What is the speed of light in vacuum (approximately)?
A
3 × 10^8 m/s
B
3 × 10^6 m/s
C
3 × 10^10 m/s
D
3 × 10^5 m/s
Correct Answer:
A. 3 × 10^8 m/s
Explanation:
The speed of light in vacuum is approximately 3 × 10^8 meters per second or 300,000 km/s.
Q.22
Easy
Which hormone regulates blood sugar levels in the human body?
A
Adrenaline
B
Thyroxine
C
Insulin
D
Cortisol
Correct Answer:
C. Insulin
Explanation:
Insulin, produced by the pancreas, regulates blood glucose levels by promoting glucose uptake and storage.
Q.23
Easy
What is the chemical formula of common salt?
A
KCl
B
NaCl
C
CaCl2
D
MgCl2
Explanation:
Common salt is sodium chloride (NaCl), composed of sodium and chlorine ions.
Q.24
Easy
Which of the following is a renewable source of energy?
A
Coal
B
Solar energy
C
Natural gas
D
Petroleum
Correct Answer:
B. Solar energy
Explanation:
Solar energy is a renewable source that can be replenished naturally, while coal, natural gas, and petroleum are non-renewable fossil fuels.
Q.25
Easy
Which acid is present in the human stomach?
A
Acetic acid
B
Hydrochloric acid
C
Citric acid
D
Sulfuric acid
Correct Answer:
B. Hydrochloric acid
Explanation:
Hydrochloric acid (HCl) is secreted by the stomach lining and helps in the digestion of proteins.
Q.26
Easy
Which vitamin is synthesized by the human body when exposed to sunlight?
A
Vitamin A
B
Vitamin B
C
Vitamin D
D
Vitamin C
Correct Answer:
C. Vitamin D
Explanation:
Vitamin D is produced by the body when skin is exposed to ultraviolet rays from the sun.
Q.27
Easy
Which gas is used for respiration by most organisms?
A
Nitrogen
B
Oxygen
C
Carbon dioxide
D
Hydrogen
Correct Answer:
B. Oxygen
Explanation:
Oxygen is essential for aerobic respiration in most organisms. It is used in cellular respiration to produce energy (ATP).
Q.28
Easy
Which of the following is not a state of matter?
A
Solid
B
Liquid
C
Gas
D
Energy
Correct Answer:
D. Energy
Explanation:
The four fundamental states of matter are solid, liquid, gas, and plasma. Energy is not a state of matter; it is a property or capability of matter to do work.
Q.29
Easy
What is the atomic number of Carbon?
Explanation:
Carbon has an atomic number of 6, meaning it has 6 protons in its nucleus. Its atomic mass is approximately 12.
Q.30
Easy
Which of the following is a non-renewable source of energy?
A
Solar energy
B
Wind energy
C
Coal
D
Hydroelectric energy
Explanation:
Coal is a non-renewable fossil fuel that takes millions of years to form. Solar, wind, and hydroelectric are renewable sources.
