CBSE Class 11 Physics MCQs Set 2

Question. When a rolling solid cylinder reaches the bottom of the slope, its linear velocity is...
A. √ gh
B. √ 2gh
C. mgh
D. √(4gh/3)
Answer: D

Question. For ideal gas, the graph of PV → P is...
A. a parabola
B. a hyperbola
C. inclined with P-axis
D. parallel to P-axis
Answer: D

Question. A spherical drop of mercury has a diameter of 6.0 x 10^-3 m. If the surface tension of mercury is 0.5 N/m, then the pressure inside the drop will exceed the pressure outside by about...
A. 42 Pa
B. 330 Pa
C. 167 Pa
D. 170 Pa
Answer: B

Question. A lift attendant has a mass of 70 kg. When the lift is going up with a constant acceleration of 1 m/s², the force acting upwards on him is...
A. zero
B. 70 N
C. 770 N
D. 700 N
Answer: C

Question. A body is moved along a straight line by a machine delivering constant power. The distance moved by the body in time t is proportional to...
A. t^1/2
B. t^3/4
C. t^3/2
D. t²
Answer: C

Question. The angular velocity of a body is changed from ω₁ to ω₂ by changing its moment of inertia. If no torque acts on the body then the ratio of initial radius of gyration to the final radius of gyration is...
A. ω₁ : ω₂
B. ω₂ : ω₁
C. √ω₁ : √ω₂
D. √ω₂ : √ω₁
Answer: C

Question. Two parallel plates carry opposite charges such that the electric field in the space between them is in upward direction. An electron is shot in the space and parallel to the plates. Its deflection from the original direction will be...
A. downwards
B. upwards
C. circular
D. none
Answer: D

Question. Compton effect is associated to...
A. X-rays
B. β-rays
C. γ-rays
D. positive rays
Answer: A

Question. If the magnitude of gravitational force is 1, the relative magnitude of strong force is...
A. 10^-13 
B. 10^-38 
C. 10³⁸
D. 10¹³
Answer: C

Question. In an elastic collision...
A. momentum is conserved but not kinetic energy 
B. kinetic energy is conserved but not momentum
C. both momentum and kinetic energy are conserved 
D. neither omentum nor kinetic energy is conserved
Answer: A

Question. In a crystal the angles between the edges of the faces and between the faces themselves are...
A. right angles
B. acute angles
C. obtuse angles
D. constant
Answer: D

Question. The equation of continuity indicates that the velocity of the fluid is greater at
A. narrow cross-section
B. broad cross-section
C. entry point
D. exit point
Answer: A

Question. The internal energy of an ideal gas is dependent on...
A. its temperature only 
B. its temperature and volume
C. its temperature and pressure
D. its temperature, pressure and volume
Answer: A

Question. The field at any point on the surface of the conductor is...
A. zero
B. parallel to the surface
C. perpendicular to the surface
D. neither parallel nor perpendicular to the surface
Answer: C

Question. A magnetic iron bar is strongly heated. Its magnetic field...
A. becomes stronger
B. becomes weaker 
C. reverses its direction 
D. does not change
Answer: B

Question. The angle subtended by the secondary bow at the eye is about...
A. 41°
B. 47°
C. 53°
D. 60°
Answer: C

Question. If M and L are respectively the mass and luminosity of a star, then L = Mα, where...
A. 0<α<1
B. α<0
C. 1<α<2
D. 2<α<4
Answer: D

Question. 'T' is period of oscillation of an object performing SHM. Its potential energy is zero at some instant. The time taken to attain maximum potential energy is...
A. T
B. T/2
C. T/4
D. T/8
Answer: C

Question. A sonar signal sent vertically downwards from a ship is reflected from the ocean floor and detected by a microphone on the keel 0.4 s after transmission. If speed of sound in water is 1500 m/s, the depth of the ocean in metre is...
A. 150
B. 300
C. 600
D. 7500
Answer: B

Question. A car of mass M is turning a corner of radius r. The coefficient of friction between the wheels and the horizontal road surface is μ. The maximum speed with which the car can turn the corner without skidding is given by..
A. Mrg
B. √Mrg
C. √ μrg
D. (μrM)/g
Answer: C

Question. The altitude of geostationary satellite above the earth's surface is approximately...
A. 35900 km
B. 42300 km
C. 11.2 km
D. 24040 km
Answer: A

Question. In order to emit electromagnetic radiation, an object must be at a temperature...
A. above 0 K
B. above 0°C
C. above that of its surroundings
D. high enough for it to glow
Answer: A

Question. A 200 m long copper wire has a resistance of 2 ohm. Its cross-sectional area is ... (take ρ = 1.7 x 10^-8 ohm-meter)
A. 0.0017 mm²
B. 1.7 mm²
C. 3.4 mm²
D. 5.3 mm²
Answer: D

Question. The unit of conductivity is...
A. ohm-meter
B. ohm/meter
C. mho-meter
D. mho/meter
Answer: C

Question. When the lead-storage cell is completely discharged, the specific gravity of the electrolyte becomes
A. 1.285
B. 1.825
C. 1.5
D. 1.15
Answer: D

Question. Two solenoids A and B have equal number of turns. The length of A is twice that of B and the cross-sectional area of A is half that of B. Other things being similar, the ratio of their inductances LA/LB is equal to...
A. 1
B. 2
C. 4
D. 1/4
Answer: A

Question. In a resistive circuit, the power factor is...
A. π
B. 1
C. √ 2
D. √(1/2)
Answer: B

Question. The impedance of a parallel RLC circuit at resonance is...
A. less than R
B. more than R
C. equal to R
D. any of the above
Answer: C

Question. Longitudinal waves do not exhibit...
A. refraction
B. reflection
C. diffraction
D. polarization
Answer: D

Question. If E₁ is the energy of a photon of ultraviolet light and E₂ that of a photon of red light, then...
A. E₁/E₂ = 1
B. E₁ is smaller than E₂
C. E₁ is greater than E₂
D. E₁ - E₂ = 0
Answer: C

Question. T is the period of oscillation for a spring-mass system on earth. Its period on moon is...
A. T
B. 6T
C. T/6
D. √ 6T
Answer: A

Question. In a stretched string, the speed of waves depends on...
A. the tension in the string
B. the amplitude
C. the wavelength
D. the acceleration due to gravity
Answer: A

Question. For a plane curved path with radius of curvature R without slope the maximum safe velocity of the vehicle(v) is proportional to...
A. R
B. R²
C. √R
D. 1/R
Answer: B

Question. Two projectiles A and B are projected with same initial velocity. The direction of A makes an angle αA = π/4 with the horizontal.The direction of B makes an angle αB with the horizontal. The range of A will be double that of B for αB equal to...
A. π/8
B. π/2
C. π/3
D. π/12
Answer: D

Question. A frictionless heat engine can be 100% efficient only its exhaust temperature is...
A. equal to its input temperature
B. 0°C
C. less than the input temperature
D. 0 K
Answer: D

Question. The resistance of conductor is R. The resistance of another conductor of identical material and equal length with twice the diameter is...
A. R/4
B. R/2
C. 2R
D. 4R
Answer: A

Question. The magnitude of the magnetic field B at a point on the axis near the centre of the infinitely long solenoid having n turns per unit length and carrying a current I is given by...
A. μnI
B. μI/n
C. (μnI)/4π
D. μI/4πn
Answer: A

Question. The impedance of a circuit does not depend on...
A. f
B. I
C. C
D. R
Answer: B

Question. Shadows are never completely dark because of...
A. interference
B. diffraction
C. polarization
D. reflection
Answer: B

Question. Threshold frequency is the characteristic of...
A. the incident radiation
B. the emitted electrons
C. the metal
D. both radiation and the metal
Answer: C

Question. In the hydrogen spectrum,the seriesv obtained in the visible region is...
A. Balmer series
B. Lyman series
C. Paschen series
D. Brackett series
Answer: A

Question. Out of four different atoms:₄₆A²², ₄₈B²², ₄₆C²³, ₄₄D²⁰, the pair of isotones is...
A. A and B
B. B and C
C. A and C
D. A and D
Answer: D

Question. In a common-base circuit, the current gain is...
A. 0
B. 1
C. less than 1
D. greater than 1
Answer: C

Question. The magnitude of the resultant of two forces is a minimum when the angle between them is...
A. 0°
B. 45°
C. 90°
D. 180°
Answer: D

Question. Work done on the particle in uniform circular motion is...
A. always positive
B. always negative 
C. always zero 
D. directly proportional to the force
Answer: C

Question. An 800-kg car moving at 80 kmph collides head-on with a 1200-kg car moving at 40 kmph. If they stick together, the wreckage now has an initial speed of...
A. 8 kmph
B. 40 kmph
C. 56 kmph
D. 60 kmph
Answer: A

Question. Fluids possess...
A. only volume elasticity
B. rigidity and volume elasticity
C. only rigidity
D. volume elasticity and tensile elasticity
Answer: A

Question. A water-proofing agent...
A. reduces angle of contact
B. increases angle of contact
C. decreases surface tension
D. increases surface area
Answer: B

Question. A certain container holds 1 kg air at atmospheric pressure. When an additional 1 kg of air is pumped into the container at constant temperature, the pressure is...
A. 0.5 atm
B. 1 atm
C. 2 atm
D. 4 atm
Answer: C

Question. If Q is the charge on either of the plates of the capacitor and V is the potential difference across the capacitor with capacitance C, what is not true is...
A. C = Q/V
B. V α Q
C. Q/V = constant
D. VQ = constant
Answer: D

Question. The origin of all magnetic fields lies in...
A. atoms of iron
B. magnetic domains
C. moving charges
D. permanent magnets
Answer: C

Question. The effective atmosphere of sun is called...
A. photosphere
B. chromosphere
C. corona
D. stratosphere
Answer: B

Question. A 4 litre gas cylinder contains neon gas at 12 kPa. Another cylinder with 8 litre capacity is at same temperature and contains argon gas at 24 kPa. When the two are connected, the total pressure will be...
A. 16 kPa
B. 18 kPa
C. 20 kPa
D. 36 kPa
Answer: C

Question. Eddy currents can be of use in...
A. dynamo armatures
B. moving coil galvanometers
C. transformer cores
D. all of the above.
Answer: B

Question. A tube closed at one end and containing air, produces the fundamental note of frequency 512 Hz when excited. If the tube is open at both ends, the fundamental frequency that can be excited in Hz is...
A. 1024
B. 512
C. 256
D. 128
Answer: A

Question. The process by which a heavy nucleus splits into two nuclei is known as...
A. fusion
B. β-decay
C. fission
D. γ-emission
Answer: C

Question. A uniform chain of length L and mass M is lying on a smooth table and one-third of its length is hanging vertically down over the edge of the table. If 'g' is the acceleration due to gravity, the work required to pull the hanging parton to the table is...
A. MgL
B. MgL/3
C. MgL/9
D. MgL/8
Answer: D

Question. Out of the following which is the most elastic ?
A. rubber
B. glass
C. steel
D. plastic
Answer: C

Question. Amagat's isothermal graphs are in the form of...
A. PV→T
B. PV→P
C. P→V
D. PV→V
Answer: B

Question. An ideal heat engine absorbs heat at 127° and rejects heat at 77°. Efficiency of the engine is...
A. 12.5%
B. 28%
C. 68%
D. 39%
Answer: A

Question. The equation applicable in the adiabatic process of n mole ideal gas is...
A. ΔU = nC_pΔT
B. ΔU = nC_vΔT
C. ΔQ = nC_vΔT
D. ΔQ = nC_pΔT
Answer: B

Question. In a Carnot's engine, the working substance is...
A. ideal gas
B. steam
C. petrol
D. CO₂
Answer: A

Question. Two particles A and b initially at rest, move towards each other under a mutual force of attraction. At the instant when the speed of A is v and the speed of B is 2v, the speed of centre of mass of the system is
A. zero
B. v
C. 1.5v
D. 3v
Answer: A

Question. Imagine a light planet revolving around a very massive star in a circular orbit of radius R with a period of revolution T. The gravitational force of attraction between the planet and the star is proportional to R^(-5/2), then T² is proportional to...
A. R³  
B. R^(7/2)
C. R^(3/2)
D. R^3.75
Answer: B

Question. Electrical conductivity increases with the increase in temperature of...
A. P-type semiconductor
B. N-type semiconductor
C. intrinsic semiconductor
D. none
Answer: C

Question. Amount of charge in coulomb required to deposit one gram equivalent of substance by electrolysis is...
A. 96500
B. 48 x 10^-10
C. 6 x 10²⁴  
D. 9600
Answer: A

Question. A camera lens is adjusted to f/4 and has an effective diameter of 2.0 cm. Its focal length is...
A. 0.2 cm
B. 1.6 cm
C. 2.0 cm
D. 8.0 cm
Answer: D

Question. The self inductance of a long solenoid is directly affected by changes in all but...
A. the number of turns
B. the current
C. the area of cross section
D. the relative permeability of the core
Answer: B

Question. Which of the following is not the unit of energy ?
A. joule
B. erg
C. newton.metre
D. dyne
Answer: D

Question. All collisions conserve...
A. kinetic energy
B. momentum
C. both kinetic energy and momentum
D. neither of kinetic energy and momentum
Answer: B

Question. If a rocket of initial mass m is to rise from its launching pad, its initial thrust must exceed...
A. mg/2
B. mg
C. 2mg
D. mg²/2
Answer: B

Question. 9 gram of water contains approximately...
A. 6 x 10²³ molecules of water
B. 6 x 10²³ atoms of oxygen
C. 6 x 10²³ atoms of hydrogen
D. 3 x 10²³ atoms of hydrogen
Answer: C

Question. A cable can support a maximum load of W without exceeding the elastic limit. If it is replaced by a cable of same material but half as long and half the diameter, the elastic limit will not be exceeded by the new cable up to a load of...
A. W/4
B. W/2
C. W
D. 2W
Answer: A

Question. Surface tension does not depend on...
A. surface area
B. the type of liquid
C. temperature
D. medium in contact with the liquid
Answer: A

Question. -40° F is equal to...
A. -40° C
B. -8°
C C. -72° C 
D. -104° C
Answer: A

Question. The magnitude of the field within a conductor...
A. depends on the shape of the conductor
B. is always zero
C. is always positive 
D. may be zero or positive
Answer: B

Question. A permanent magnet does not exert force on...
A. an unmagnetized iron bar
B. a magnetized iron bar
C. a stationary electric charge
D. a moving electric charge
Answer: C

Question. A primary rainbow cannot be seen by an observer looking up if the altitude of the Sun exceeds...
A. 10°
B. 20°
C. 22.5°
D. 40°
Answer: D

Question. According to the descending order of temperature the stars are classified in to the orders O,B,A,F,G,K and M. Our Sun comes in the order...
A. A
B. B
C. G
D. K
Answer: C

Question. Position of the centre of mass of a rigid body depends on...
A. its shape only
B. distribution of its matter only
C. both its shape and distribution of matter
D. its position relative to the earth.
Answer: C

Question. Force is to linear motion as _____ is to rotational motion.
A. acceleration
B. torque
C. moment of inertia
D. angular momentum
Answer: B

Question. A hole is drilled to the centre of the earth and a stone is dropped in to it. When the stone is at the earth's centre, compared to the values at the earth's surface...
A. its mass and weight both change
B. its mass and weight both are zero
C. its mass is unchanged and its weight is zero
D. its mass is zero and its weight is unchanged
Answer: C

Question. For an IC engine, the thermal efficiency depends on...
A. the compression ratio
B. the speed of the piston
C. the temperature of working medium
D. the diameter of the cylinder
Answer: A

Question. A 12-V potential difference is applied across a series combination of four 6-ohm resistors. The current in each resistor is...
A. 0.5 A
B. 2 A
C. 8 A
D. 18 A
Answer: A

Question. The temperature at which the thermo emf becomes zero is known as the...
A. neutral temperature
B. absolute temperature
C. inverse temperature
D. thermoelectric temperature
Answer: C

Question. A transformer uses the principle of...
A. self-induction
B. mutual induction
C. variable resistance
D. electrostatic attraction
Answer: B

Question. If V and V_m are the instantaneous and maximum values, respectively , of voltage in an a.c. circuit, then the mean value of the voltage is...
A. V_m sinωt
B. √ 2 V_m
C. V_m/√ 2
D. none of the above
Answer: D

Question. Electromagnetic waves having wavelengths greater than 200 m are called...
A. sky waves
B. ground waves
C. micro waves
D. X-rays
Answer: B

Question. If θ_m is the angle of diffracted wave with the direction of incidence and d is the width of slit, then mth order minima is obtained for sinθ_m equal to...
A. mλ/d
B. dλ/m
C. md/λ
D. m/λd
Answer: A

Question. As a sample of a radioactive element decays, its half-life...
A. decreases
B. increases
C. remains the same
D. changes exponentially.
Answer: C