What is the chemical formula for table salt?
A NaCl B KCl C CaCl₂ D MgCl₂
Table salt is sodium chloride (NaCl), composed of sodium and chlorine ions in a 1:1 ratio.
Which vitamin is produced by the skin when exposed to sunlight?
A Vitamin A B Vitamin B C Vitamin D D Vitamin E
Vitamin D is synthesized in the skin upon exposure to ultraviolet (UV) radiation from sunlight.
Which element has the atomic number 6?
A Oxygen B Nitrogen C Carbon D Helium
Carbon has atomic number 6, meaning it has 6 protons in its nucleus. It is the basis of all organic compounds.
Which organ in the human body produces insulin?
A Liver B Pancreas C Kidney D Stomach
The pancreas produces insulin, a hormone that regulates blood glucose levels. The beta cells in the pancreas secrete this hormone.
Which of the following is a renewable energy source?
A Coal B Petroleum C Solar energy D Natural gas
Solar energy is renewable as the sun's energy is continuously available. Coal, petroleum, and natural gas are non-renewable fossil fuels.
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What is the boiling point of water at standard atmospheric pressure?
A 90°C B 100°C C 110°C D 80°C
Water boils at 100°C (212°F) at standard atmospheric pressure of 1 atm or 101.325 kPa.
Which blood group is considered a universal recipient?
A A B B C AB D O
AB blood group is the universal recipient because it has both A and B antigens, allowing it to receive blood from all groups.
Which element is the most abundant in the Earth's atmosphere?
A Oxygen B Nitrogen C Argon D Carbon dioxide
Nitrogen comprises about 78% of Earth's atmosphere, followed by oxygen at about 21%.
What is the principal source of energy for the Earth?
A The Moon B The Sun C Geothermal energy D Nuclear reactions in Earth's core
The Sun is the primary source of energy for Earth, providing energy through radiation that drives weather, climate, and photosynthesis.
Which of the following is an example of a physical change?
A Rusting of iron B Burning of paper C Melting of ice D Digestion of food
Melting of ice is a physical change as water remains H₂O but changes from solid to liquid state. Other options are chemical changes.
What is the process by which an electric current is generated using a magnetic field?
A Magnetization B Electromagnetic induction C Polarization D Ionization
Electromagnetic induction is the process where a changing magnetic field produces an electric current, as discovered by Faraday.
Which gas is used in welding and cutting of metals?
A Nitrogen B Oxygen C Acetylene D Hydrogen
Acetylene (C₂H₂) is commonly used in oxy-acetylene welding and cutting due to its high flame temperature of about 3,300°C.
In Newton's third law of motion, if object A exerts a force on object B, what does object B do?
A Exerts an equal and opposite force on A B Exerts a smaller force on A C Exerts no force on A D Exerts a greater force on A
Newton's third law states that for every action, there is an equal and opposite reaction. Forces always occur in pairs.
Which of the following is a non-renewable energy source?
A Solar energy B Wind energy C Coal D Hydroelectric energy
Coal is a fossil fuel and non-renewable energy source. Solar, wind, and hydroelectric are renewable sources.
Which of the following is the hardest naturally occurring substance on Earth?
A Graphite B Diamond C Quartz D Feldspar
Diamond is the hardest naturally occurring substance, rating 10 on the Mohs hardness scale.
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
The speed of light in vacuum is approximately 3 × 10^8 meters per second or 300,000 km/s.
Which hormone regulates blood sugar levels in the human body?
A Adrenaline B Thyroxine C Insulin D Cortisol
Insulin, produced by the pancreas, regulates blood glucose levels by promoting glucose uptake and storage.
What is the chemical formula of common salt?
A KCl B NaCl C CaCl2 D MgCl2
Common salt is sodium chloride (NaCl), composed of sodium and chlorine ions.
Which of the following is the largest organ in the human body by mass?
A Heart B Brain C Liver D Lung
The liver is the largest internal organ by mass, weighing approximately 1.5 kg in adults.
What happens to the density of water when it freezes into ice?
A Density increases B Density decreases C Density remains the same D Density becomes zero
Ice has lower density than water, which is why ice floats on water. Water expands when it freezes.
