Science Olympiad : General Science MCQ set - 3
Q. Speed of light in vacuum ?
Ans: 3×108 m/s
Explanation: Light travels fastest in vacuum, at approximately 300 million meters per second.
Q. Fastest communication wave ?
Ans: Light wave
Explanation: Optical signals travel at the speed of light, making light waves the fastest for communication.
Q. Force per unit area ?
Ans: Pressure
Explanation: Pressure describes how much force acts on each unit of area.
Q. SI unit of pressure ?
Ans: Pascal (Pa)
Explanation: 1 Pascal = 1 Newton of force acting on 1 square meter.
Q. Instrument to measure pressure of gases ?
Ans: Manometer
Explanation: A manometer compares gas pressure with atmospheric pressure using a liquid column.
Q. Device to measure atmospheric pressure ?
Ans: Barometer
Explanation: Barometers detect changes in air pressure to forecast weather.
Q. Instrument used to measure humidity ?
Ans: Hygrometer
Explanation: Hygrometers measure moisture content in the air.
Q. Instrument used to measure altitude ?
Ans: Altimeter
Explanation: Altimeters use air pressure to calculate height above sea level.
Q. Instrument used to measure heat ?
Ans: Calorimeter
Explanation: A calorimeter measures heat changes in chemical or physical processes.
Q. Energy possessed by a body due to motion?
Ans: Kinetic energy
Explanation: Any moving object has kinetic energy, proportional to its mass and speed.
Q. Energy possessed by a body due to position ?
Ans: Potential energy
Explanation: Stored energy arises from an object's height or position in a field.
Q. Energy stored in food and fuel ?
Ans: Chemical energy
Explanation: Food and fuels store energy in chemical bonds.
Q. Energy obtained from the Sun ?
Ans: Solar energy
Explanation: The Sun gives heat and light through nuclear fusion.
Q. The unit of electric charge ?
Ans: Coulomb (C)
Explanation: 1 Coulomb is the charge carried by 6.25×10186.25 \times 10^{18}6.25×1018 electrons.
Q. Instrument used to detect electric current ?
Ans: Galvanometer
Explanation: A galvanometer shows small currents through needle deflection.
Q. Work done when 1 Coulomb of charge is moved through 1 Volt ?
Ans: 1 Joule
Explanation: Work = Charge × Potential difference ⇒ 1C×1V=1J1C × 1V = 1J1C×1V=1J.
Q. Rate of doing work ?
Ans: Power
Explanation: Power tells how fast work is done or energy is used.
Q. Work done per unit time ?
Ans: Power
Explanation: Power = Work ÷ Time, measured in watts.
Q. The weakest force in nature ?
Ans: Gravitational force
Explanation: Gravity is weakest but acts over the longest distance.
Q. The strongest force in nature ?
Ans: Nuclear force
Explanation: Strong nuclear force binds protons and neutrons inside the nucleus.
Q. Who discovered X-rays ?
Ans: Wilhelm Roentgen
Explanation: In 1895, Roentgen discovered X-rays while experimenting with cathode rays.
Q. Who discovered radioactivity ?
Ans: Henri Becquerel
Explanation: He observed natural radiation from uranium salts in 1896.
Q. Who discovered the neutron ?
Ans: James Chadwick
Explanation: Chadwick identified the neutral particle in 1932.
Q. Who gave the theory of relativity ?
Ans: Albert Einstein
Explanation: His theory explains space, time, energy, and gravity.
Q. Who discovered the law of gravitation ?
Ans: Isaac Newton
Explanation: Newton concluded gravity acts between all masses and explained planetary motion.