Science Olympiad : Basic Physics MCQ set - 8
Q. What is the SI unit of mass ?
Ans: Kilogram (kg)
Explanation: Kilogram is the internationally accepted base unit for measuring mass.
Q. What is the SI unit of time ?
Ans: Second (s)
Explanation: Second is defined based on atomic clock vibrations for highest accuracy.
Q. What is the SI unit of length ?
Ans: Metre (m)
Explanation: One metre is the distance light travels in vacuum in 1/299,792,458 seconds.
Q. What is the SI unit of temperature ?
Ans: Kelvin (K)
Explanation: Kelvin measures absolute temperature starting from absolute zero.
Q. What is the SI unit of luminous intensity ?
Ans: Candela (cd)
Explanation: Candela measures visible light emitted by a source.
Q. What is the SI unit of electric charge ?
Ans: Coulomb (C)
Explanation: One coulomb is the charge carried by 1 ampere current in 1 second.
Q. Work done ?
Ans: Work = Force × Distance
Explanation: Work is done when a force moves an object through a distance.
Q. Power ?
Ans: Power = Work / Time
Explanation: Power shows how fast work is done.
Q. Force ?
Ans: Force = Mass × Acceleration
Explanation: This is Newton’s 2nd law describing how mass responds to acceleration.
Q. Momentum ?
Ans: Momentum = Mass × Velocity
Explanation: It measures the quantity of motion an object has.
Q. Energy cannot be created or destroyed — which law ?
Ans: Law of Conservation of Energy
Explanation: Energy only changes form; total amount remains constant.
Q. 1 Horsepower (HP) = ?
Ans: 746 Watt
Explanation: One horsepower equals the power needed to lift 550 pounds 1 foot in 1 second.
Q. Which law explains “Action & Reaction”?
Ans: Newton’s 3rd Law
Explanation: Every action has an equal and opposite reaction.
Q. Which law explains “Inertia”?
Ans: Newton’s 1st Law
Explanation: A body continues in its state unless an external force acts.
Q. Which law explains F = ma ?
Ans: Newton’s 2nd Law
Explanation: It relates force with mass and acceleration.
Q. Unit of gravitational constant (G) ?
Ans: Nm²/kg²
Explanation: Derived from Newton’s law of gravitation.
Q. Escape velocity on Earth ?
Ans: 11.2 km/s
Explanation: Minimum speed needed to escape Earth’s gravitational pull.
Q. Value of G (gravitational constant) ?
Ans: 6.67 × 10⁻¹¹ Nm²/kg²
Explanation: This constant measures gravitational force between masses.
Q. Which mirror always forms virtual, erect & diminished image ?
Ans: Convex mirror
Explanation: Its outward curve spreads light rays apart.
Q. Which mirror can form both real and virtual images ?
Ans: Concave mirror
Explanation: Converging mirror forms real or virtual images depending on object distance.
Q. The bending of light is called ?
Ans: Refraction
Explanation: Light bends when it moves between media of different densities.
Q. The bouncing back of light is called ?
Ans: Reflection
Explanation: Light returns after striking a smooth surface.
Q. Splitting of white light into 7 colors is ?
Ans: Dispersion
Explanation: Prism separates light due to different wavelengths.
Q. Speed of light is maximum in ?
Ans: Vacuum
Explanation: No obstacles or medium particles slow it down.
Q. Which color of light has the shortest wavelength ?
Ans: Violet
Explanation: Violet light has highest frequency and shortest wavelength.