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105 questions from UPSC CSE Prelims GS Paper 1 on Physics (Science & Technology). Spanning from 1995 to 2021. Practice with show/hide answers and detailed explanations.
105
Questions
21
Years
53
Easy
51
Moderate
Based on 105 questions across 21 years, UPSC has consistently tested aspirants' understanding of Physics within the broader Science & Technology syllabus. The questions range from factual recall to application-based analysis.
Recent trends show UPSC moving towards statement-based questions that combine multiple aspects of Physics. Aspirants should focus on understanding concepts rather than memorizing isolated facts.
Q: In a pressure cooker, the temperature at which the food is cooked depends mainly upon which of the following? 1. Area of the hole in the lid 2. Temperature of the flame 3. Weight of the lid Select the correct answer using the code given below:
Q: Consider the following phenomena: 1. Light is affected by gravity. 2. The Universe is constantly expanding. 3. Matter warps its surrounding space-time. Which of the above is/are the prediction/predictions of Albert Einstein’s General Theory of Relativity, often discussed in media?
Q: In the context of modern scientific research, consider the following statements about ‘IceCube’, a particle detector located at South Pole, which was recently in the news: 1. It is the world’s largest neutrino detector, encompassing a cubic kilometre of ice. 2. It is a powerful telescope to search for dark matter. 3. It is buried deep in the ice. Which of the statements given above is/are correct?
Q: Ball bearings are used in bicycles, cars, etc., because
Q: Consider the following phenomena: 1. Size of the sun at dusk 2. Colour of the sun at dawn 3. Moon being visible at dawn 4. Twinkle of stars in the sky 5. Polestar being visible in the sky Which of the above are optical illusions?
Q: Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this? 1. Dispersion 2. Refraction 3. Internal reflection Select the correct answer using the codes given below.
Q: The known forces of nature can be divided into four classes, viz., gravity, electromagnetism, weak nuclear force and strong nuclear force. With reference to them, which one of the following statements is not correct?
Q: The efforts to detect the existence of Higgs boson particle have become frequent news in the recent past. What is/are the importance/ importances of discovering this particle? 1. It will enable us to understand as to why elementary particles have mass. 2. It will enable us in the near future to develop the technology of transferring matter from one point to another without traversing the physical space between them. 3. It will enable us to create better fuels for nuclear fission. Select the correct answer using the codes given below.
Q: A team of scientists at Brookhaven National Laboratory including those from India created the heaviest anti-matter (anti-helium nucleus). What is/are the implication/implications of the creation of anti-matter? 1. It will make mineral prospecting and oil exploration easier and cheaper. 2. It will help probe the possibility of the existence of stars and galaxies made of anti-matter. 3. It will help understand the evolution of the universe.
Q: Consider the following statements: If there were no phenomenon of capillarity 1. it would be difficult to use a kerosene lamp 2. one would not be able to use a straw to consume a soft drink 3. the blotting paper would fail to function 4. the big trees that we see around would not have grown on the Earth Which of the statements given above are correct?
Q: The surface of a lake is frozen in severe winter, but the water at its bottom is still liquid. What is the reason ?
Q: If a potato is placed on a pure paper plate which is white and unprinted and put in a microwave oven, the potato heats up but the paper plate does not. This is because
Q: Two trains leave New Delhi at the same time. One travels north at 60 kmph and the other travels south at 40 kmph. After how many hours will the trains be 150 km apart?
Q: India-based Neutrino Observatory is included by the Planning Commission as a mega science project under the 11th Five-Year Plan. In this context, consider the following statements: 1. Neutrinos are chargeless elementary particles that travel close to the speed of light. 2. Neutrinos are created in nuclear reactions of beta decay. 3. Neutrinos have a negligible, but non-zero mass. 4. Trillions of Neutrinos pass through human body every second. Which of the statements given above are correct?
Q: What is the principle by which a cooling system (Radiator) in a motor car works?
Q: Indiscriminate disposal of used fluorescent electric lamps causes mercury pollution in the environment. Why is mercury used in the manufacture of these lamps?
Q: Which one of the following types of waves are used in a night vision apparatus ?
Q: Which one among the following has the highest energy ?
Q: In the year 2008, which one of the following conducted a complex scientific experiment in which sub-atomic particles were accelerated to nearly the speed of light ?
Q: Which one of the following laser types is used in a laser printer?
Q: Consider the following statements: 1. A widely used musical scale called diatonic scale has seven frequencies. 2. The frequency of the note Sa (स) is 256 Hz and that of Ni (नी) is 512 Hz. Which of the statements given above is/are correct?
Q: How can the height of a person who is six feet tall be expressed (approximately) in nanometres?
Q: A person is sitting in a car which is at rest. The reaction from the road at each of the four wheels of the car is R. When the car runs on a straight level road, how will the reaction at either of the front wheels vary?
Q: Assertion (A): In the visible spectrum of light, red light is more energetic than green light. Reason (R): The wavelength of red light is more than that of green light.
Q: Assertion (A): Radio waves bend in a magnetic field. Reason (R): Radio waves are electromagnetic in nature.
Q: Consider the following statements : 1. If magenta and yellow coloured circles intersect, the intersected area will have red colour. 2. If cyan and magenta coloured circles intersect, the intersected area will have blue colour. Which of the statements given above is/are correct?
Q: Consider the following statements: 1. A flute of smaller length gives waves of lower frequency. 2. Sound travels in rocks in the form of longitudinal elastic waves only. Which of the statements given above is/are correct?
Q: Four wires of the same material and of the dimensions given below are stretched by equal loads separately. Which one of them will be elongated the maximum?
Q: Assertion (A): A jet aircraft moving at Mach number equal to 1 travels faster at an altitude of 15 km than while moving at Mach number equal to 1 near sea level. Reason (R): The velocity of sound depends on the temperature of the surrounding medium.
Q: Three identical vessels A, B and C are filled with water, mercury and kerosene respectively up to an equal height. The three vessels are provided with identical taps at the bottom of the vessels. If the three taps are opened simultaneously, then which vessel is emptied first?
Q: In which one among the following is the speed of sound maximum?
Q: There are 8 equidistant points A, B, C, D, E, F, G and H in the clockwise direction on the periphery of a circle. In a time-interval t, a person reaches from A to C with uniform motion while another person reaches the point E from the point B during the same time-interval with uniform motion. Both the persons move in the same direction along the circumference of the circle and start at the same instant. How much time after the start will the two persons meet each other?
Q: Which one of the following is printed on a commonly used fluorescent tube light?
Q: Assertion (A): In our houses, the current in AC electricity line changes direction 60 times per second. Reason (R): The frequency of alternating voltage supplied is 60 hertz.
Q: A car is running on a road at a uniform speed of 60 km/hr. The net resultant force on the car is
Q: A spherical body moves with a uniform angular velocity ω around a circular path of radius r. Which one of the following statements is correct?
Q: A weightless rubber balloon is filled with 200 cc of water. Its weight in water is equal to
Q: A person stands at the middle point of a wooden ladder which starts slipping between a vertical wall and the floor of a room, while plane. The path traced by a person standing at the middle point of the slipping ladder is
Q: A hydrogen-inflated polythene balloon is released from the surface of the earth. As the balloon rises to an altitude up in the atmosphere, it will
Q: Consider the following statements: 1. Steam at 100 °C and boiling water at 100 °C contain the same amount of heat. 2. Latent heat of fusion of ice is equal to the latent heat of vaporization of water. 3. In an air-conditioner, heat is extracted from the room air at the evaporator coils and is rejected out at the condenser coils. Which of these statements is/are correct?
Q: Consider the following statements: A four-wheel vehicle moving on a sharp circular path at high speed will 1. Overturn about its outer wheels. 2. Overturn about its inner wheels. 3. Skid outwards. 4. Skid inwards. Which of these statements are correct?
Q: Diffusion of light in the atmosphere takes place due to
Q: An oil tanker is partially filled with oil and moves forward on a level road with uniform acceleration. The free surface of oil then
Q: Which one of the following statements is correct?
Q: If the radius of the earth were shrunk by one per cent, its mass remaining the same, the value of ‘g’ on the earth’s surface would
Q: Regarding the atom of a chemical element, the magnetic quantum number refers to
Q: A solid cube just gets completely immersed in water when a 0.2 kg mass is placed on it. If the mass is removed, the cube is 2 cm above the water level. What is the length of each side of the cube?
Q: Consider the following natural phenomena: 1. Terrestrial heating 2. Reflection of light 3. Refraction of light 4. Diffraction of light Due to which of these phenomena is mirage formed?
Q: Consider the following statements: 1. Light of longer wavelength is scattered much more than light of shorter wavelength. 2. The speed of visible light in water is 0.95 times its speed in vacuum. 3. Radio waves are produced by rapidly oscillating electrical currents. 4. To detect over-speeding vehicles, police use the Doppler effect of reflected short radio waves. Which of these statements are correct?
Q: A hollow sphere of radius R, a hollow cube of side R and a thin circular plate of radius R, made up of the same material, are all heated to 20 °C above room temperature. When left to cool in the room, which of them will reach the room temperature first?
Q: Assertion (A): An iron ball floats on mercury but gets immersed in water. Reason (R): The specific gravity of iron is more than that of mercury.
Q: Two wires have their lengths, diameters and resistivities, all in the ratio of 1 : 2. If the resistance of the thinner wire is 10 ohms, the resistance of the thicker wire is
Q: Assertion (A): A stick is dipped in water in a slanting position. If observed sideways, the stick appears short and bent at the surface of water. Reason (R): The light coming from the stick undergoes scattering from water molecules giving the stick a short and bent appearance.
Q: Assertion (A): A piece of copper and a piece of glass are heated to the same temperature. When touched, thereafter, the copper piece appears hotter than the glass piece. Reason (R): The density of copper is more than that of glass.
Q: Assertion (A): The boiling point of water decreases as the altitude increases. Reason (R): The atmospheric pressure increases with altitude.
Q: When light waves pass from air to glass, the variables affected are
Q: When water is heated from 0 °C to 10 °C, its volume
Q: Match List I with List II and select the correct answer using the codes given below the Lists: List I (Characteristic) I. Zero mass II. Fractional charge III. Fractional spin IV. Integral spin List II (Particle) A) Positron B) Neutrino C) Quark D) Phonon
Q: The mass of a body on Earth is 100 kg (acceleration due to gravity, gₑ = 10 m/s²). If acceleration due to gravity on the Moon = gₑ/6, then the mass of the body on the moon is
Q: Consider the following statements: A simple pendulum is set into oscillation. Then I. the acceleration is zero when the bob passes through the mean position. II. in each cycle the bob attains a given velocity twice. III. both acceleration and velocity of the bob are zero when it reaches its extreme position during its oscillation. IV. the amplitude of oscillation of the simple pendulum decreases with time. Which of these statements are correct?
Q: Which of the following distance–time graphs (x–t) represents one-dimensional uniform motion?
Q: Which one of the following does a TV remote control unit use to operate a TV set?
Q: A noise level of 100 decibels would correspond to
Q: Fluorescent tubes are fitted with a choke. The choke coils
Q: When a CD (Compact Disc used in audio and video systems) is seen in sunlight, rainbow-like colours are seen. This can be explained on the basis of the phenomenon of
Q: Assertion (A): A man standing on a completely frictionless surface can propel himself by whistling. Reason (R): If no external force acts on a system, its momentum cannot change.
Q: Assertion (A): In a motion picture, usually 24 frames are projected every second over the whole length of the film. Reason (R): An image formed on the retina of eye persists for about 0.1 s after the removal of stimulus.
Q: Assertion (A): Small glass beads fixed on traffic signals glow brightly when light falls upon them. Reason (R): Light is totally reflected when the angle of incidence exceeds a certain critical value and light travelling in a denser medium is reflected back into a rarer medium.
Q: Assertion (A): Large cold storage plants use ammonia as refrigerant while domestic refrigerators use chlorofluorocarbons. Reason (R): Ammonia can be liquified at ambient temperatures at low pressures.
Q: Consider the following statement: An ordinary light bulb has a rather short life because the I. filament wire is not uniform. II. bulb cannot be evacuated completely. III. wires supporting the filament melt at high temperatures. Which of the above statements are correct?
Q: Match List I (Quantity) with List II (Units) and select the correct answer using the codes given below the Lists: List I I. High speed II. Wavelength III. Pressure IV. Energy List II A) Mach B) Angstrom C) Pascal D) Joule Codes:
Q: Consider the following statements: I. If a person looks at a coin which is in a bucket of water, the coin will appear to be closer than it really is. II. If a person under water looks at a coin above the water surface, the coin will appear to be at a higher level than it really is. Which of the above statements is/are correct?
Q: Endoscopy, a technique used to explore the stomach or other inner parts of the body is based on the phenomenon of
Q: Strips of two metals A and B are firmly joined together as shown in the figure. On heating, A expands more than B does. If this joined strip is heated, then it will appear as:
Q: Low temperatures (Cryogenics) find application in
Q: A hunter aims his gun at a point between the eyebrows of a monkey sitting on a branch of a tree. Just as he fires, the monkey jumps down. The bullet will
Q: A fuse is used in main electric supply as a safety device. Which one of the following statements about the fuse is correct?
Q: A ball is dropped from the top of a high building with a constant acceleration of 9.8 m/s². What will be its velocity after 3 seconds?
Q: Assertion (A): The temperature of a metal wire rises when an electric current is passed through it. Reason (R): Collision of metal atoms with each other releases heat energy.
Q: The tendency of a liquid drop to contract and occupy minimum area is due to
Q: Which one of the following is a vector quantity?
Q: Which one of the following is a valid conclusion?
Q: The working principle of a washing machine is
Q: A smooth inclined plane is inclined at an angle θ with the horizontal as shown in the figure. A body starts from rest and slides down the inclined surface. The time taken by the body to reach the bottom is
Q: A girl is swinging on a swing in sitting position. When the same girl stands up, the period of swing will
Q: A boat which has a speed of 5 km/hr in still water crosses a river of width 1 km along the shortest possible path in 15 minutes. The velocity of the river water in km/hr is
Q: I. ‘A’ stood first in the race. II. ‘C’ led all the way. III. ‘D’ ran faster than others in the later part of the race. Of these statements
Q: When an air bubble at the bottom of a lake rises to the top, it will
Q: When a mirror is rotated by an angle of θ, the reflected ray will rotate by
Q: A truck, a car and a motor cycle have equal kinetic energies. If equal stopping ...
Q: A liquid is flowing in a streamlined manner through a cylindrical pipe. Along a section containing the axis of the pipe, the flow profile will be
Q: The variation of displacement (d) with time (t) in the case of a particle falling freely under gravity from rest is correctly represented by which of the following graphs?
Q: Total internal reflection can take place when light travels from
Q: Assertion (A): Transformer is useful for stepping up or stepping down voltages. Reason (R): Transformer is a device used in D.C. circuits. In the context of the above two statements, which one of the following is correct?
Q: Domestic electrical wiring is basically a
Q: A simple machine helps a person doing
Q: The alpha particle carries two positive charges. Its mass is very nearly equal to that of
Q: 105. A parachutist jumps from a height of 5000 metres. The relationship between his falling speed ‘v’ and the distance fallen through ‘d’ is best represented as (four graphs labelled a, b, c, d).
Q: 106. Which one of the following can be used to confirm whether drinking water contains a gamma-emitting isotope or not?
Q: 107. The normal temperature of human body on the Kelvin scale is
Q: 108. When the same note is played on a sitar and a flute, the sound produced can be distinguished from each other because of the difference in
Q: 109. Assertion (A): A diamond sparkles more than a glass imitation cut to the same shape. Reason (R): The refractive index of diamond is less than that of glass. In the context of the above two statements, which one of the following is correct?
Q: 111. Optical fibre works on the principle of
Q: 112. Suppose a rocketship is receding from the earth at a speed of 2⁄10th the velocity of light. A light in the rocketship appears blue to the passengers on the ship. What colour would it appear to an observer on the earth?
Q: An air bubble in water will act like a
UPSC has asked 105 questions on Physics in GS Paper 1 Prelims between 1995 and 2021. This sub-topic falls under Science & Technology.
Questions on Physics have appeared in UPSC Prelims in the following years: 2021, 2018, 2015, 2013, 2012, 2011, 2010, 2009, 2008, 2007, 2006, 2004, 2003, 2002, 2001, 2000, 1999, 1998, 1997, 1996, 1995. The topic has appeared in 21 out of 31 years.
Among 105 questions on Physics: 53 are easy, 51 are moderate, and 1 are difficult. Most questions test conceptual understanding of the topic.
