General Physics Question For Competitive Exam, Physics Question for SSC, NDA, Railway and Police Examination, General Science Physics Question
General Physics Question For Competitive Exam
Question: The best malleable metal is -
(A) Aluminum
(B) Silver
(C) Gold
(D) Lead
Question: The early attempt to classify elements as metals and non-metals was made by -
(A) Mendeleev
(B) Lother Meyer
(C) Lavoisier
(D) Henry Moseley
Question: The magnet is strongest near the -
(A) Poles of the magnet
(B) Ends of the magnet
(C) Centre of the magnet
(D) On equator point from the poles of the magnet
Question: Which is the device used to detect and measure small electric current in a circuit?
(A) Transformer
(B) Galvanometer
(C) Thermometer
(D) Electromagnetic Induction
Question: The lowest temperature at which an oil gives sufficient vapours to form an explosive mixture with air is known as -
(A) Flash Point
(B) Smoke Point
(C) Explosive Point
(D) Acidic Flux
Question: The value of G in the formula for gravitational force depends on -
(A) Mass of the earth only
(B) The radius of the earth only
(C) Both mass and radius of the earth
(D) Neither mass nor the radius of the earth
Question: When a hanging carpet is beaten with a stick, the dust particles in it start coming out of it. This phenomenon can be explained by making use of -
(A) Newton's first law of motion
(B) Newton's second law of motion
(C) Newton's third law of motion
(D) Newton's law of gravitation
Question: The numerical ratio of displacement to distance for a moving object is -
(A) Always Less than 1
(B) Equal to 1 or more than 1
(C) Always more than 1
(D) Equal to 1 or less than 1
Question: Who was the first scientist of the world to use symbols to represent elements in a short way?
(A) Dalton
(B) Jons Jakob Berzelious
(C) Neils Bohr
(D) Dmitri Mendeleev
Question: Which of the following is/ are physical changes?
I. Melting of iron rod
II. Rusting of iron metal
III. Bending of an iron rod
IV. Drawing a wire of iron metal
Correct code is -
(A) Only I, II and III
(B) Only I, II and IV
(C) Only I, III and IV
(D) Only II, III and IV
Question: Milk of Magnesia is a -
(A) Colloid
(B) True solution
(C) Homogeneous Mixture
(D) Suspension
Question: Which mineral is also known as fool's gold?
(A) Quartz
(B) Magneti
(C) Pyrite
(D) Fluorite
Question: The physics phenomenon when, in polar regions like Alaska and Northern Canada, a splendid display of colours is seen in the sky is called a/an -
(A) aurora borealis
(B) star shower
(C) active galactic nucleus
(D) star's intrinsic luminosity
Question: Which of the following metals in pure form has the highest melting point?
(A) Tungsten
(B) Copper
(C) Platinum
(D) Gold
Question: All the mixtures containing a solid and a liquid can be separated by -
I. Centrifugation
II. Evaporation
III. Crystallisation
IV. Chromatography
Correct code is -
(A) Only I
(B) Only II and III
(C) I, II, III and IV
(D) Only III and IV
Question: Which of the following is not a characteristic of a physical change?
(A) It is a temporary change
(B) It is usually an irreversible change
(C) Very little heat (or light) energy is usually absorbed or given out
(D) The mass of a substance does not alter in a physical change
Question: Sound cannot travel through -
(A) Solids
(B) Liquids
(C) Gases
(D) Vaccum
Question: What is the correct ascending order of the following substances in relation to their density (kg/ m(C)?
(A) Aluminium, Iron, Mercury, Gold
(B) Gold, Iron, Aluminium, Mercury
(C) Mercury, Iron, Gold, Aluminium
(D) Iron, Gold, Mercury, Aluminium
Question: Which of the following metals exists in the liquid state?
(A) Sodium
(B) Mercury
(C) Silver
(D) Chromium
Question: Which of the following metals is not strong?
(A) Sodium
(B) Gold
(C) Silver
(D) Iron
Question: The device used for producing electric current is called -
(A) Generator
(B) Galvanometer
(C) Ammeter
(D) Motor
Question: Sun derives its energy from -
(A) The fusion of hydrogen nuclei into helium nuclei
(B) The fusion of helium nuclei into hydrogen nuclei
(C) The fission of hydrogen nuclei
(D) The fission of helium nuclei
Question: Which of the following statements is/ are true?
I. A concave mirror is used as a head mirror by ENT surgeons.
II. The concave metal dishes are used in dish antennas (or the dish aerials) of televisions.
(A) Only I is correct
(B) Only II is correct
(C) I and II both are correct
(D) Neither I nor II is correct
Question: Which of the following materials cannot be used to make a lens?
(A) Water
(B) Glass
(C) Plastic
(D) Clay
Question: Which one of the following is a non-metallic mineral?
(A) Iron
(B) Mica
(C) Copper
(D) Bauxite
Question: Which of the following are the characteristics of electromagnetic waves?
1. They are elastic waves.
2. They can also move in a vacuum.
3. They have electric and magnetic components which are mutually perpendicular.
4. They move with a speed equal to 3 lakh meters per second.
Select the correct answer using the code given below -
(A) 1, 2, 3 and 4
(B) 1, 2 and 4 only
(C) 2 and 3 only
(D) 3 and 4 only
Question: Radiations coming from the Sun are mostly in the form of -
(A) light only
(B) light and long-wavelength infrared
(C) light and short-wavelength infrared
(D) both short and long-wavelength infrared
Question: The temperature of a place on one sunny day is 113 in a Fahrenheit scale. The Kelvin scale reading of this temperature will be -
(A) 318 K
(B) 45 K
(C) 62.8 K
(D) 335.8 K
Question: Compared to audible sound waves, ultrasound waves have -
(A) higher speed
(B) higher frequency
(C) longer wavelength
(D) both higher speed and frequency
Question: Which one of the following statements regarding cathode rays is not correct?
(A) Cathode ray particles are electrons
(B) Cathode ray particles start from the anode and move towards the cathode
(C) In the absence of electrical and magnetic fields, cathode rays travel in straight lines
(D) Television picture tubes are cathode-ray tubes
Question: Light rays move in straight lines. But through an optional fiber, they can move in any type of zigzag path because -
(A) the holes through the fiber are extremely fine
(B) light rays are absorbed at the entry end and relieved at the exit end of the fiber
(C) scattering of light occurs inside the fiber
(D) successive total internal reflections occur as a ray moves through the fiber
Answer: (D) successive total internal reflections occur as a ray moves through the fiber
Explanation: Successive total internal reflections occur as a ray of light moves through an optical fiber.
Question: Water is heated with a coil of resistance R connected to domestic supply. The rise of temperature of water will depend on -
1. Supply voltage.
2. Current passing through the coil.
3. Time for which voltage is supplied.
Select the correct answer from among the following -
(A) 1, 2 and 3
(B) 1 and 2 only
(C) 1 only
(D) 2 and 3 only
Answer: (A) 1, 2 and 3
Question: The loudness of sound depends upon the -
(A) velocity of sound waves in the medium
(B) amplitude of the sound waves
(C) frequency of the sound waves
(D) frequency and velocity of the sound waves
Answer: (B) amplitude of the sound waves
Question: Net movement of water from a dilute to a concentrated solution through a selectively permeable membrane is called -
(A) Diffusion
(B) Dispersion
(C) Osmosis
(D) Absorption
Answer: (C) Osmosis
Explanation: Osmosis is a process by which molecule of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.
Question: 10 g of ice at -100C is mixed with 10 g of water at 00C. The amount of heat required to raise the temperature of mixture to 100C is -
(A) 400 cal
(B) 550 cal
(C) 1050 cal
(D) 1200 cal
Answer: (C) 1050 cal
Question: Which one of the following statements regarding lenses is not correct?
(A) A convex lens produces both real and virtual images
(B) A concave lens produces both real and virtual images
(C) A convex lens can produce images equal, greater and smaller than the size of the object
(D) A concave lens always produces images smaller than the size of the object
Answer: (B) A concave lens produces both real and virtual images
Explanation: A concave lens produces only virtual images.
Question: If the work done on the system or by the system is zero, which one of the following statements for a gas kept at a certain temperature is correct?
(A) Change in internal energy of the system is equal to flow of heat in or out of the system
(B) Change in internal energy of the system is less than heat transferred
(C) Change in internal energy of the system is more than the heat flow
(D) Cannot be determined
Answer: (A) Change in internal energy of the system is equal to flow of heat in or out of the system
Explanation: If the work done on the system or by the system is zero, then for a gas kept at a certain temperature, the change in internal energy of the system is equal to flow of heat in or out of the system.
Question: A student measures certain lengths using a meter scale having least count equal to 1 mm. Which one of the following measurements is more precise?
(A) 0.50 mm
(B) 29.07 mm
(C) 0.925 m
(D) 910 mm
Answer: (C) 0.925 m
Question: A car starts from Bengaluru, goes 50 km in a straight line towards south, immediately turns around and returns to Bengaluru. The time taken for this round trip is 2 hours. The magnitude of the average velocity of the car for this round trip -
(A) is 0.
(B) is 50 km/ hr.
(C) is 25 km/ hr.
(D) cannot be calculated without knowing acceleration.
Answer: (A) is 0
Question: The sum of emf's and potential differences around a closed loop equals zero is a consequence of -
(A) Ohm's law
(B) Conservation of charge
(C) Conservation of momentum
(D) Conservation of energy
Answer: (D) Conservation of energy
Explanation: Conservation of energy (Kirchhoff's second law of voltage) : This law states that the sum of all voltages and e.m.f. around any closed loop in a circuit must be equal to zero.
Question: A solid disc and a solid sphere have the same mass and same radius. Which one has the higher moment of inertia about its center of mass?
(A) The disc
(B) The sphere
(C) Both have the same moment of inertia
(D) The information provided is not sufficient to answer the question
Answer: (A) The disc
Question: If an object moves at a non-zero constant acceleration for a certain interval of time, then the distance it covers in that time -
(A) depends on its initial velocity
(B) is independent of its initial velocity
(C) increases linearly with time
(D) depends on its initial displacement
Answer: (A) depends on its initial velocity
Question: The raw materials used for the manufacture of Portland cement are -
(A) Lime, silica and Sulphur dioxide
(B) Lime, silica and carbon dioxide
(C) Lime, silica and alumina
(D) Lime, silica and boric acid
Answer: (C) Lime, silica and alumina
Question: Which one of the following statements about diamond and graphite is not correct?
(A) Diamond has a tetrahedral structure, whereas graphite has a hexagonal planar structure
(B) Both physical and chemical properties of diamond and graphite are different
(C) Graphite is soft but diamond is hard
(D) Graphite is a good conductor of electricity while diamond is not
Answer: (B) Both physical and chemical properties of diamond and graphite are different
Question: Which one of the following statements is correct?
(A) Both boiling and evaporation are surface phenomena
(B) Boiling is a surface phenomenon, but evaporation is a bulk phenomenon
(C) Both boiling and evaporation are bulk phenomena
(D) Boiling is a bulk phenomenon, but evaporation is a surface phenomenon
Answer: (D) Boiling is a bulk phenomenon, but evaporation is a surface phenomenon
Question: Which one of the following statements about glass is not correct?
(A) Glass is often said to be a supercooled liquid
(B) Glass has no definite melting point
(C) Soda glass is harder than Pyrex glass
(D) Boron is present in Pyrex glass
Answer: (C) Soda glass is harder than Pyrex glass
Question: When a ball bounces off the ground, which of the following changes suddenly? (Assume no loss of energy to the floor)
(A) Its speed
(B) Its momentum
(C) Its kinetic energy
(D) Its potential energy
Answer: (B) Its momentum
Question: Which one of the following statements regarding Ohm's law is not correct?
(A) Ohm's law is an assumption that current through a conductor is always directly proportional to the potential difference applied to it.
(B) A conducting device obeys Ohm's law when the resistance of a device is independent of magnitude and polarity of applied potential difference.
(C) A conducting material obeys Ohm's law when the resistance of material is independent of the magnitude and direction of applied electric field.
(D) All homogeneous materials obey Ohm's law irrespective of whether the field is within range or strong.
Answer: (D) All homogeneous materials obey Ohm's law irrespective of whether the field is within range or strong
Question: In which of the following phenomena do heat waves travel along straight line with the speed of light?
(A) Thermal conduction
(B) Thermal convection
(C) Thermal radiation
(D) Both, thermal conduction and radiation
Answer: (C) Thermal radiation
Question: Let there be an object having some chemicals in it. It starts moving with a uniform velocity v and a chemical reaction starts happening. In this case, which of the following statement/s is/ are correct?
1. Chemical reactions happening in the system cannot change the velocity v of the center of mass of the object.
2. Chemical reactions happening in the system cannot change kinetic energy of the particles inside with respect to the center of mass of object.
Select the correct answer using the code given below -
(A) 1 only
(B) 2 only
(C) Both 1 and 2
(D) Neither 1 nor 2
Answer: (A) 1 only
Question: A thin disc and a thin ring, both have mass M and radius R. Both rotate about axes through their center of mass and are perpendicular to their surfaces at the same angular velocity. Which of the following is true?
(A) The ring has higher kinetic energy
(B) The disc has higher kinetic energy
(C) The ring and the disc have the same kinetic energy
(D) Kinetic energies of both the bodies are zero since they are not in linear motion
Answer: (A) The ring has higher kinetic energy
Question: First electro chemical cell was designed by -
(A) Leclanche
(B) Faraday
(C) Galvanic
(D) None of the above
Answer: (D) None of the above
Question: The velocity of sound in any gas depends upon -
(A) Wavelength of sound only
(B) Density and elasticity of gas
(C) Intensity of sound waves only
(D) Amplitude and frequency of sound
Answer: (B) Density and elasticity of gas
Question: It is difficult to cook at high altitude because -
(A) There is less oxygen in the air
(B) Due to fall in temperature, one has to give more heat
(C) Due to decrease in atmospheric pressure the boiling point of water decreases
(D) Of high moisture content at higher altitude
Answer: (C) Due to decrease in atmospheric pressure the boiling point of water decreases
Question: The poorest conductor of heat among the following is -
(A) copper
(B) lead
(C) mercury
(D) zinc
Answer: (C) mercury
Explanation: Mercury is a poor conductor of heat, but a fair conductor of electricity. Mercury has a unique electron configuration which strongly resists removal of an electron, making it behave similarly to noble gas elements. As a result, mercury forms weak bonds and is a liquid at room temperature.
Question: Which of the following does not change when light travels from one medium to another?
(A) Velocity
(B) Wavelength
(C) Frequency
(D) Refractive index
Answer: (C) Frequency
Question: 'Light-year' is a unit of -
(A) time
(B) speed
(C) distance
(D) intensity of light
Answer: (C) distance
Explanation: A light-year is a unit of distance, not time. A light-year is how astronomers measure distance in space. It's defined by how far a beam of light travels in one year - a distance of six trillion miles.
Question: Faraday constant depends on the -
(A) amount of the electrolyte
(B) current passed in the electrolyte
(C) volume of the solvent in which the electrolyte is dissolved
(D) is a universal constant
Answer: (A) amount of the electrolyte
Question: On heating, the resistance of a semiconductor -
(A) increases
(B) decreases
(C) remains same
(D) first increases and then decreases
Answer: (B) decreases
Question: The total resistance of a circuit having two parallel resistors is 1.403 kilo-ohm. If one of the resistors is 2.0 kilo-ohm, then the other resistor will be -
(A) 1.403 kilo-ohm
(B) 2.0 kilo-ohm
(C) 3.403 kilo-ohm
(D) 4.70 kilo-ohm
Answer: (D) 4.70 kilo-ohm
Question: People prefer to wear cotton clothes in summer season. This is due to the fact that cotton clothes are -
(A) good absorbers of water
(B) good conveyors of heat
(C) good radiators of heat
(D) good absorbers of heat
Answer: (A) good absorbers of water
Question: The frequency (in Hz) of a note that is one octave higher than 500 Hz is -
(A) 375
(B) 750
(C) 1000
(D) 2000
Answer: (C) 1000
Question: If the speed of a moving magnet inside a coil increases, the electric current in the coil -
(A) increases
(B) decreases
(C) reverses
(D) remains the same
Answer: (A) increases
Question: If an object is at rest, then the time (X-axix) versus distance (Y-axis) graph -
(A) is vertical
(B) is horizontal
(C) has 450 positive slope
(D) has 450 negative slope
Answer: (B) is horizontal
Question: Rate of evaporation increases with -
(A) an increase of surface area
(B) an increase in humidity
(C) a decrease in wind speed
(D) a decrease of temperature
Answer: (A) an increase of surface area
Question: The value of the slope of a normal demand curve is -
(A) positive
(B) negative
(C) zero
(D) infinity
Answer: (B) negative
Question: Magnification is -
(A) actual size of specimen/ observed size
(B) observed size of specimen/ actual size
(C) actual size of specimen - observed size
(D) actual size of specimen x observed size
Answer: (B) observed size of specimen/ actual size
Question: Which one of the following is active transport?
(A) It is the movement of a substance against a diffusion gradient with the use of energy from respiration.
(B) It is the movement of a substance against a diffusion gradient without the use of energy.
(C) It is the movement of a substance against a diffusion gradient with the use of energy from photosynthesis.
(D) IT is the movement of a substance along a diffusion gradient with the use of energy from respiration.
Answer: (A) It is the movement of a substance against a diffusion gradient with the use of energy from respiration
Question: Rutherford's alpha-particle scattering experiment on thin gold foil was responsible for the discovery of -
(A) electron
(B) proton
(C) atomic nucleus
(D) neutron
Answer: (C) atomic nucleus
Question: The rate of evaporation of liquid does not depend upon -
(A) temperature
(B) its surface are exposed to the atmosphere
(C) Its mass
(D) humidity
Answer: (C) Its mass
Question: Bose-Einstein Condensate is -
(A) solid state of matter
(B) fifth state of matter
(C) plasma
(D) state of condensed matter
Answer: (B) fifth state of matter
Question: Which one of the following instruments is used for locating submerged objects in the ocean?
(A) Audio meter
(B) Galvanometer
(C) Sextant
(D) Sonar
Answer: (D) Sonar
Explanation: Sonar (Sound Navigation Ranging) is a technique that uses sound propagation to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.
Question: Which of the following is a naturally occurring hardest substance on the earth?
(A) Graphite
(B) Wurtzite boron nitride
(C) Iron
(D) Diamond
Answer: (D) Diamond
Explanation: Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. It is composed of pure carbon and is the hardest natural occurring substance on the earth.
Question: Driving force of an ecosystem is -
(A) Carbohydrate
(B) Biomass
(C) Carbon
(D) Solar energy
Answer:(D) Solar energy
Question: An ultimate source of energy stored in fossil fuels is -
(A) Earth
(B) Sun
(C) Sea
(D) Moon
Answer: (B) Sun
Question: Which one of the following colours of white light is least deviated by the glass prism?
(A) Green colour
(B) Red colour
(C) Violet colour
(D) Orange colour
Answer: (B) Red colour
Explanation: Red colour of white light is least deviated by the glass prism while violet colour deviates most.
Question: Which of the following is used in fire alarm?
(A) Photo cell
(B) Water
(C) Solar cell
(D) None of the above
Answer: (A) Photo cell
Question: A 100 W electric bulb is used for 10 hours a day. How many units of energy are consumed in 30 days?
(A) 1
(B) 10
(C) 30
(D) 300
Answer: (C) 30
Question: An echo is heard after 5 seconds of the production of sound which moves with a speed of 340 m/s. What is the distance of the mountain from the source of sound which produced the echo?
(A) 0.085 km
(B) 0.85 km
(C) 0.17 km
(D) 1.7 km
Answer: (B) 0.85 km
Question: What is the more common name for solid carbon dioxide?
(A) Potash
(B) Quick Silver
(C) Epsom
(D) Dry Ice
Answer: (D) Dry Ice
Question: Which of the following is a highly reactive metal?
(A) Sodium
(B) Calcium
(C) Magnesium
(D) Aluminium
Answer: (A) Sodium
Question: Food cans are coated with tin and not zinc because -
(A) Zinc is costlier than tin
(B) Zinc has a higher melting point than tin
(C) Zinc is more reactive than tin
(D) Zinc is less reactive than tin
Answer: (C) Zinc is more reactive than tin
Question: Which metal is used for making the filaments of electric bulbs?
(A) Tungsten
(B) Copper
(C) Silver
(D) Brass
Answer: (A) Tungsten
Explanation: Tungsten metal is used for making the filaments of electric bulbs because it has a very high melting point of 33800C.
Question: Which of the following statements is/ are correct about 'Bar Magnet'?
I. The Bar Magnet is a permanent magnet.
II. The strength of a permanent magnet cannot be changed.
III. A permanent magnet produces a comparatively weak force of attraction.
Correct code is -
(A) Only I
(B) Only I and II
(C) I, II, III all
(D) None of the above
Answer: (C) I, II, III all
Question: The correct relation between the radius of curvature R and focal length f of a spherical mirror is -
(A) R = f
(B) R = 2f
(C) R = 3f
(D) R = 4f
Answer: (B) R = 2f
Question: A lemon kept in water in a glass tumbler appears to be larger than its actual size. It is because of -
(A) reflection of light
(B) scattering of light
(C) refraction of light
(D) polarization of light
Answer: (C) refraction of light
Explanation: As a result of phenomenon of refraction, a lemon kept in the glass tumbler appears to be larger than its actual size.
Question: Name the scientist who first used a glass prism to obtain the spectrum of sunlight -
(A) C. V. Raman
(B) Lord Rayleigh
(C) Isaac Newton
(D) S. Chandrashekhar
Answer: (C) Isaac Newton
Explanation: Isaac Newton was the first scientist who used a glass prism to obtain the spectrum of sunlight. This spectrum has seven colours.
Question: This cost of energy to operate an industrial refrigerator that consumes 5 kW power working 10 hours per day for 30 days will be -
(Given that the charge per kW.h of energy = Rs. (D)
(A) Rs. 600
(B) Rs. 6,000
(C) Rs. 1,200
(D) Rs. 1,500
Answer: (B) Rs. 6,000
Question: Which one of the following statements regarding magnetic field is not correct?
(A) Magnetic field is a quantity that has direction and magnitude
(B) Magnetic field lines are closed curves
(C) Magnetic field lines are open curves
(D) No two magnetic field lines are found to cross each other
Answer: (C) Magnetic field lines are open curves
Explanation: Out of the magnet, the direction of magnetic lines of force, is from north pole to south pole and inside the magnet, it is from south pole to north pole.
Question: Which one of the following types of radiations has the smallest wavelength?
(A) Microwaves
(B) Infra-red
(C) Visible light
(D) X-rays
Answer: (D) X-rays
Explanation: In the spectrum of solar radiation, gamma rays have the shortest wavelength and next is the X-ray, which has the longer wavelength than the gamma radiation.
Question: The instrument used for detecting the presence of electric current in a circuit is -
(A) Refractometer
(B) Galvanometer
(C) Viscometer
(D) Diffractometer
Answer: (B) Galvanometer
Question: The Sun appears reddish during sunrise and sunset. The phenomenon in optics which is responsible for this appearance of the Sun is -
(A) Reflection
(B) Total internal reflection
(C) Scattering
(D) Interference
Answer: (C) Scattering
Explanation: Due to the phenomenon of scattering of light, the sun appears reddish during sunrise and sunset, Red portion of the spectrum scatters the least.
Question: A lens has a power of + 2.0 Diopter. Which one of the following statements about the lens is true?
(A) The lens is concave and has a focal length of 0.5 meter
(B) The lens is convex and has a focal length of 0.5 meter
(C) The lens is convex and has a focal length of 0.5 meter
(D) The lens is concave and has a focal length of 2.0 meter
Answer: (C) The lens is convex and has a focal length of 0.5 meter
Question: Which one of the following was the first mineral acid discovered?
(A) Sulphuric acid
(B) Hydrochloric acid
(C) Nitric acid
(D) Phosphoric acid
Answer: (A) Sulphuric acid
Explanation: Out of the given options, sulphuric acid was discovered first of all. Gebar was the discoverer of sulphuric acid.
Question: In case of a concave mirror, if an object is kept between principal focus F and pole P of the mirror, then which one of the following statements about the image is not correct?
(A) The image will be virtual
(B) The image will be enlarged or magnified
(C) The image will be formed at infinity
(D) The image will be erect
Answer: (C) The image will be formed at infinity
Question: In an incandescent electric bulb, the filament of the bulb is made up of which metal?
(A) Aluminium
(B) Copper
(C) Tungsten
(D) Silver
Answer: (C) Tungsten
Question: Which one of the following is not the unit of energy?
(A) Joule
(B) Watt-hr
(C) Newton-metre
(D) kg-metre/sec2
Answer: (C) Newton-metre
Question: Two planets orbit the Sun in circular orbits, with their radius of orbit as R1 = R and R2 = 4 R. Ratio of their periods (T1/T(B) around the Sun will be -
(A) 1/ 16
(B) 1/ 8
(C) 1/ 4
(D) 1/ 2
Answer: (D) 1/ 2
Question: A metallic wire having resistance of 20 Ω is cut into two equal parts in length. These parts are then connected in parallel. The resistance of this parallel combination is equal to -
(A) 20 Ω
(B) 10 Ω
(C) 5 Ω
(D) 15 Ω
Answer: (C) 5 Ω
Question: Light of uniform intensity impinges perpendicularly on a totally reflecting surface. If the area of the surface is halved, the radiation force on it will become -
(A) double
(B) half
(C) four times
(D) one fourth
Answer: (B) half
Question: Which one of the following statements about sound is not correct?
(A) Sound travels at a speed slower than the speed of light
(B) Sound waves are transverse waves
(C) Sound waves are longitudinal waves
(D) Sound travels faster in moist air than in dry air
Answer: (B) Sound waves are transverse waves
Explanation: Sound waves are longitudinal waves. Hence, no polarization takes place with sound waves.
Question: When the short circuit condition occurs, the current in the circuit -
(A) becomes zero
(B) remains constant
(C) increases substantially
(D) keeps on changing randomly
Answer: (C) increases substantially
Explanation: When a state of short circuit takes place, current in the circuit increases substantially.
Question: Which of the following statements is not correct regarding the travel of sound waves?
(A) Sound waves can travel through water
(B) Sound waves can travel through air
(C) Sound waves can travel through steel
(D) Sound waves can travel through vacuum
Answer: (D) Sound waves can travel through vacuum
Explanation: Medium is essential for propagation of sound. There is no medium in vacuum.
Question: Which of these devices is used to increase the power of a signal?
(A) Amplifier
(B) Voltage regulator
(C) Attenuator
(D) All of the above
Answer: (B) Voltage regulator
Explanation: An amplifier is an electronic device that can increase the power of a signal.
Question: Sound velocity is usually larger in solids than in liquids and gases because -
(A) solids are more elastic than liquids and gases
(B) solids are less elastic than liquids and gases
(C) volumetric expansion coefficients of liquids and gases are higher than solids
(D) frequency of sound waves decreases in solids due to Doppler shift
Answer: (A) solids are more elastic than liquids and gases
Explanation: A substance is labelled more elastic if it offers greater resistance to deformation than other bodies, so that it can be stretched less than others.
Question: A container is filled with water at 40C. The water will overflow if the temperature of water is -
(A) Increased
(B) Decreased
(C) Increased or decreased
(D) None of the above
Answer: (C) Increased or decreased
Explanation: The reason is the anomalous expansion of water. The maximum density of water occurs at 40C. So the water expands whether it is heated above 40C or cooled below 40C.
Question: The pencil leads are made of mainly -
(A) Lithium
(B) Charocoal
(C) Lead
(D) Graphite
Answer: (D) Graphite
Question: Which of the following is a real image?
(A) An image formed in a plain mirror
(B) An image formed by a diverging lense
(C) The image of actors formed on a cinema screen
(D) An image formed by a convex mirror
Answer: (C) The image of actors formed on a cinema screen
Question: In which of the following metals did the Karddamaka Kshatrapas issue the very rare coins?
(A) Copper
(B) Silver
(C) Potin
(D) Gold
Answer: (A) Copper
Question: A measured temperature in Fahrenheit scale is 2000F. What will be its value in Celsius scale?
(A) 93.30C
(B) 400C
(C) 990C
(D) 300C
Answer: (A) 93.30C
