Science Olympiad : MCQ practice set - 7
Q: What is the SI unit of force ?
Ans: Newton (N)
Explanation: Force is measured in Newton as defined by Newton’s second law.
Q: What is the SI unit of work ?
Ans: Joule (J)
Explanation: Work is energy transfer, so its unit is Joule.
Q: What is the SI unit of power ?
Ans: Watt (W)
Explanation: Power is rate of doing work, measured in watts.
Q: What is the SI unit of energy ?
Ans: Joule (J)
Explanation: Energy and work share the same unit.
Q: What is the SI unit of pressure ?
Ans: Pascal (Pa)
Explanation: Pressure = force per unit area, measured in Pascal.
Q: What is the SI unit of electric current ?
Ans: Ampere (A)
Explanation: Ampere is the base SI unit for current.
Q: What is the SI unit of voltage ?
Ans: Volt (V)
Explanation: Voltage measures electric potential difference.
Q: What is the SI unit of resistance ?
Ans: Ohm (Ω)
Explanation: Resistance is measured in ohm based on Ohm’s law.
Q: What is the SI unit of frequency ?
Ans: Hertz (Hz)
Explanation: Frequency means cycles per second.
Q: What is the SI unit of power of a lens ?
Ans: Dioptre (D)
Explanation: Dioptre is the reciprocal of focal length in meters.
Q: Who discovered the law of gravitation ?
Ans: Isaac Newton
Explanation: Newton proposed the universal law of gravitation.
Q: What is the value of acceleration due to gravity on Earth ?
Ans: 9.8 m/s²
Explanation: It is the standard gravitational acceleration near Earth’s surface.
Q: What is the speed of light in vacuum ?
Ans: 3 × 10⁸ m/s
Explanation: Light travels fastest in vacuum.
Q: What is the speed of sound in air ?
Ans: 343 m/s
Explanation: This is its approximate speed at room temperature.
Q: Which mirror is used in car headlights ?
Ans: Concave mirror
Explanation: Concave mirrors focus light into a strong beam.
Q: Which mirror is used in rear-view mirrors ?
Ans: Convex mirror
Explanation: Convex mirrors give a wider field of view.
Q: Which lens corrects myopia (short-sightedness) ?
Ans: Concave lens
Explanation: Concave lenses diverge light to help distant vision.
Q: Which lens corrects hypermetropia (long-sightedness) ?
Ans: Convex lens
Explanation: Convex lenses converge light for near vision.
Q: Which type of lens is used in a magnifying glass ?
A: Convex lens
Explanation: Convex lenses enlarge images when object is near focus.
Q: What is the SI unit of heat ?
Ans: Joule (J)
Explanation: Heat is a form of energy measured in Joules.
Q: At what temperature are Celsius and Fahrenheit equal ?
Ans: – 40°
Explanation: –40° is the point where both scales coincide.
Q: Which instrument measures atmospheric pressure ?
Ans: Barometer
Explanation: Barometer detects changes in air pressure.
Q: Which instrument measures electric current ?
Ans: Ammeter
Explanation: Ammeter is connected in series to measure current.
Q: Which instrument measures voltage ?
Ans: Voltmeter
Explanation: Voltmeter is connected in parallel to measure potential difference.
Q: Which instrument measures resistance ?
Ans: Ohmmeter
Explanation: Ohmmeter directly measures electrical resistance.