CBSE Class 11 Physics MCQs Set 1

Question. Fermi is a unit of...
A. length
B. mass
C. time
D. electric flux
Answer: A

Question. The horizontal component of a force of 10 N inclined at 30° to the vertical is...
A. 5 N
B. 5√ 3 N
C. 3 N
D. 10/√ 3 N
Answer: A

Question. The acceleration due to gravity on Mars is 3.7 m/s². Compared with her mass and weight on the earth, an astronaut on Mars has...
A. less mass and less weight
B. more mass and more weight
C. the same mass and less weight
D. the same mass and more weight
Answer: C

Question. To keep a vehicle moving at the speed v requires a force F. The power needed is...
A. F.v
B. (1/2)F.v²
C. F/v 
D. F/v2
Answer: A

Question. When the velocity of a moving object is doubled...
A. its acceleration is doubled
B. its momentum is doubled
C. its kinetic energy is doubled
D. its potential energy is doubled
Answer: B

Question. The intermolecular potential is dependent on...
A. the shape of the molecules only
B. the molecular separation only
C. both the shape and the molecular separation 
D. none of the above
Answer: C

Question. A cable stretches by amount 'a' under a certain load. If it is replaced by a cable of the same material but half as long and half the diameter, the same load will stretch it by...
A. a/4
B. a/2
C. a
D. 2a
Answer: D

Question. A certain person's heart beats 1.2 times per second and pumps 1.0 x 10^-4 m³ of blood per beat against an average pressure of 14 kPa. The power output of the heart is...
A. 1.2 W
B. 1.4 W
C. 1.7 W
D. 12 W
Answer: C

Question. At which of the following temperatures would the molecules of a gas have twice the average kinetic energy they have at 20 °C
A. 40 °C
B. 80 °C
C. 313 °C
D. 586 °C
Answer: C

Question. For monatomic gases, C_p/C_v is equal to...
A. 1.67
B. R
C. 1.67 R
D. 1.5 R
Answer: A

Question. Of the following the one that is a vector is...
A. electric charge
B. electric field
C. electric energy
D. potential difference
Answer: B

Question. Diamagnetic materials are substances that...
A. create a strong magnetic field
B. are attracted by a magnetic field
C. are repelled by a magnetic field
D. have double magnetism
Answer: C

Question. When a ferromagnet is inserted in a current-carrying loop, the magnetic field...
A. decreases slightly
B. decreases greatly
C. does not change 
D. increases greatly
Answer: D

Question. A light ray passes through a prism with an angle of incidence θ, an angle of deviation δ and an angle of emergence ε. Minimum deviation occurs when...
A. δ = θ
B. δ = ε
C. θ = ε
D. δ = θ - ε
Answer: C

Question. The image a camera forms on the film is...
A. always real
B. always virtual
C. always erect
D. sometimes inverted
Answer: A

Question. If for the planets in solar system, r is the radius of the orbit and T is the periodic time, then the ratio r₃/T₂ is...
A. 1
B. same for all planets 
C. more for farther planets 
D. less for farther planets
Answer: B

Question. A boy swings from a rope 4.9 m long. His approximate period of oscillation is...
A. 0.5 s
B. 3.1 s
C. 4.4 s
D. 12 s
Answer: C

Question. The primary effect when the source is moving is a change in...
A. frequency
B. amplitude 
C. wavelength 
D. both frequency and amplitude
Answer: C

Question. The distance between a node and the immediate next antinode is...
A. λ
B. λ/2
C. λ/3
D. λ/4
Answer: D

Question. A thin ring has mass M and radius R. Its moment of inertia about the axis passing through its center and perpendicular to its plane is...
A. MR²
B. M²R
C. M/R²
D. M²/R
Answer: A

Question. Two satellites have periods P₁ and P₂, respectively. Their heights above the surface of the earth are h₁ and h₂, respectively. If h₁ > h₂, then...
A. P₁ > P₂
B. P₁ = P₂
C. P₁ < P₂
D. P₁₂ > P₂²
Answer: A

Question. A projectile is thrown in the direction making an angle θ with the horizontal. The projectile attains maximum height for θ equal to...
A. 0
B. π/4
C. π/2
D. π
Answer: C

Question. A Carnot engine operates between 800K and 200K. If it absorbs 8 kJ of heat in each cycle, the work done by it per cycle is...
A. 1 kJ
B. 2 kJ
C. 2.7 kJ
D. 6 kJ
Answer: B

Question. In a uniform segment of a circuit the current is proportional to the...
A. density of the segment
B. resistance of the segment
C. volume of the segment
D. potential difference at its ends
Answer: D

Question. To charge a secondary cell, what is needed is...
A. a d.c. current
B. an a.c. current
C. fresh electrolyte
D. heating 
Answer: A

Question. Two parallel wires carry current in the same direction,...
A. they attract each other
B. they repel each other
C. they neither attract nor repel
D. they attract or repel depending on current type
Answer: A

Question. If the maximum value of the induced e.m.f. is V_m and maximum r.m.s. current is √ 2 ampere for an a.c. circuit with resistance R, then the value of V_m in volt is equal to...
A. 2R
B. R
C. 1/R
D. √ 2/R
Answer: A

Question. The wavelength of light plays no role in...
A. interference
B. diffraction
C. resolving power
D. polarization
Answer: D

Question. The value of the stopping potential depends on...
A. the intensity of light
B. the frequency of light
C. the metal surface area
D. the charge on the electron
Answer: B

Question. The only atom which has no neutron in the nucleus is...
A. hydrogen
B. helium
C. oxygen
D. polonium
Answer: A

Question. In a tug-of-war match, one team is pulling with a force of 500 N. If they are exactly balanced by the other team, then the tension in the rope is...
(a) 0  
(b) 250 N   
(c) 500 N  
(d) 1000 N
Answer: C

Question. The time taken by the light to travel from Sun to earth is approximately...
(a) 8 seconds  
(b) 8 minutes  
(c) 18 seconds  
(d) 18 minutes
Answer: B

Question. A charge q is placed at the centre of the line joining two equal charges Q. The system of the three charges will be in equilibrium if q is equal to...
(a) -(Q/2)  
(b) -(Q/4)   
(c) +(Q/4)  
(d) +(Q/2)
Answer: B

Question. The velocity of sound in vacuum is 320 m/s. A pipe closed at one end has a length 1 m. Neglecting end corrections, the air column in the pipe can resonate for sound of frequency which is not equal to...
(a) 80 Hz  
(b) 240 Hz  
(c) 320 Hz  
(d) 400 Hz
Answer: C

Question5. The thermodynamic coordinate that remains constant during an adiabatic process is...
(a) temperature  
(b) pressure 
(c) density  
(d) entropy
Answer: D

Question. _____ is not contained in the nucleus of an atom...
(a) proton  
(b) electron  
(c) neutron  
(d) meson
Answer: B

Question. As an airplane climbs...
(a) its mass decreases  
(b) its mass increases  
(c) its weight decreases 
(d) its weight increases
Answer: C

Question. The unit of the force constant is...
(a) Nm  
(b) Nm²  
(c) Nm^-2  
(d) Nm
Answer: D

Question. Brownian motion increases as...
(a) the particle size increases  
(b) the particle size decreases
(c) the viscosity of the medium increases  
(d) the temperature decreases.
Answer: B

Question. Young's modulus is associated with...
(a) volume elasticity  
(b) rigidity  
(c) shear elasticity  
(d) tensile elasticity
Answer: D

Question. The force of adhesion is greater than the force of cohesion. This means that the angle of contact (θ) is equal to...
(a) 180°  
(b) 120°  
(c) 90°  
(d) 45°
Answer: D

Question. The temperature of an object is raised by 50°(c) This is equivalent to an increase in its absolute temperature of...
(a) 50 K  
(b) 323 K  
(c) 223 K  
(d) 82 K
Answer: A

Question. The total electric flux is...
(a) always positive 
(b) always negative 
(c) always zero 
(d) none of the above
Answer: D

Question. If the field lines are evenly spaced, the field is...
(a) uniform  
(b) zero  
(c) strong  
(d) weak
Answer: A

Question. Relative to its object, a real image formed by a lens is always...
(a) erect 
(b) inverted 
(c) smaller 
(d) larger
Answer: B

Question. The highest proportion of gas in the Sun is that of...
(a) hydrogen 
(b) helium 
(c) carbon dioxide 
(d) carbon monoxide
Answer: A

Question. The product of the period and frequency of a harmonic oscillation is always equal to...
(a) 1  
(b) π 
(c) 2π 
(d) A
Answer: A

Question. A direct result of superposition of waves is...
(a) resonance  
(b) a wavefront 
(c) a progressive wave  
(d) beating
Answer: D

Question. In the absence of external force the velocity of the center of mass of a system of particles is...
(a) zero 
(b) constant 
(c) maximum 
(d) minimum
Answer: B

Question. Three particles of masses 1 kg, 2 kg and 1 kg are at the points whose position vectors are i + j, 2i - j and 3i + j, respectively. The position vector of their centre of mass is...
(a) (6i + j)/4
(b) 2i
(c) (6i + j)/3
(d) 8i
Answer: B

Question. For an object above the earth's surface, if the distance of the object from earth's centre is 'd', then the acceleration due to gravity is proportional to.
(a) d
(b) d²
(c) 1/d
(d) 1/d²
Answer: D

Question. A perfectly reversible process...
(a) exists
(b) does not exist but is possible
(c) is impossible
(d) involves intermediate inequilibrium states
Answer: C

Question. The unit of resistance is...
(a) volt/second
(b) ampere/second
(c) volt.ampere
(d) volt/ampere
Answer: D

Question. The unit of magnetic flux density is...
(a) weber
(b) tesla
(c) henry
(d) faraday
Answer: B

Question. The power factor of a circuit is equal to...
(a) RZ
(b) R/Z
(c) X_L/Z
(d) X_L/Z
Answer: B

Question. Ozone layer absorbs all electromagnetic radiations having wavelength...
(a) smaller than 3 x 10^-7 m
(b) smaller than 3 x 10^-8 m
(c) greater than 3 x 10^-7 m
(d) greater than 3 x 10^-8 m
Answer: A

Question. Stationary waves are produced by...
(a) interference
(b) diffraction
(c) polarization
(d) refraction
Answer: A

Question. According to Planck's quantum theory, the emission of energy...
(a) is continuous
(b) is discontinuous
(c) does not depend on wavelength
(d) does not depend on frequency
Answer: B

Question. When an electron jumps from an orbit of higher energy E₂ to the one with lower energy E₁, the frequency of the electromagnetic radiation emitted depends on...
(a) E₂
(b) E₁
(c) E₁ + E₂
(d) E₂ - E₁
Answer: D

Question. After 10 years 75 g of an original sample of 100 g of a certain radioactive element has decaye(d) The half-life of the isotope is...
(a) 5 years
(b) 7.5 years
(c) 20 years
(d) 40 years
Answer: A

Question. In simple harmonic motion, there is always a constant ratio between the displacement of mass and its...
(a) speed
(b) acceleration
(c) period
(d) mass
Answer: B

Question. The wave intensity is proportional to the...
(a) amplitude
(b) square of amplitude
(c) frequency
(d) square of frequency
Answer: B

Question. When a rigid body rotates about an axis and the external torque is zero, then for that body _____ is constant.
(a) angular velocity
(b) moment of inertia
(c) linear momentum
(d) angular momentum
Answer: D

Question. If Q1 is the heat absorbed by the working substance and Q₂ is the heat utilized in doing work, then the efficiency of the engine is given by...
(a) 1 - (Q₁/Q₂)
(b) 1 - (Q₂/Q₁)
(c) (1 - Q₁)/Q₂
(d) (1 - Q₂)/Q₁
Answer: B

Question. Two identical resistors in parallel have an equivalent resistance of 2 Ω. If the resistors were in series, their equivalent resistance would be...
(a) 2 Ω
(b) 4 Ω 
(c) 8
(d) 16 Ω
Answer: C

Question. The value of permeability of vacuum (μ) in tesl(a)m/ampere is...
(a) 4 x 10^-7 
(b) 4π x 10^-7 
(c) 1.257 x 10^-6  
(d) 1.257 x 10⁶
Answer: C

Question. The power factor of a circuit in which X_L = X_(c)..
(a) is 0
(b) is 1
(c) depends on X_L/X_C
(d) depends on R
Answer: B

Question. It is impossible to polarize...
(a) white light
(b) radio waves
(c) X-rays
(d) sound waves
Answer: D

Question. The wave theory of light fails to explain...
(a) interference
(b) diffraction
(c) polarization
(d) black-body radiation
Answer: D

Question. The beta- disintegration of a parent element produces a daughter element which in the periodic table is...
(a) up by one step
(b) down by one step
(c) up by two steps 
(d) down by two steps
Answer: A

Question. The unit of radioactive constant(λ) of the disintegrating element is...
(a) m
(b) m/s
(c) s^-1
(d) m^-1
Answer: C

Question. The process of introducing impurity in an intrinsic semiconductor is calle(d)..
(a) diffusion
(b) doping
(c) depletion
(d) transition
Answer: B

Question. Which of the following is dimensionless?
(a) frequency
(b) stress
(c) coefficient of friction
(d) gas constant
Answer: C

Question. When the acceleration is zero, the final velocity of the object is...
(a) zero
(b) less than initial velocity 
(c) more than initial velocity 
(d) equal to initial velocity
Answer: D

Question. The coefficient of static friction for steel on ice is 0.1. The coefficient of sliding friction therefore can be
(a) 0.08
(b) 0.1 
(c) 0.11
(d) 1.1
Answer: A

Question. If a shell fired from a cannon explodes in mid-air...
(a) its total kinetic energy increases
(b) its total kinetic energy decreases
(c) its total momentum increases
(d) its total momentum decreases
Answer: A

Question. Avogadro suggested that the smallest particle of an element that can exist in free state is...
(a) atom
(b) molecule
(c) neutron
(d) ion
Answer: B

Question. An iron wire 1 m long with a square cross section 2 mm on a side is used to support a 100-kg loa(d) Its elongation is...
(a) 0.0027 mm
(b) 0.27 mm
(c) 1.3 mm
(d) 3.7 mm
Answer: C

Question. Dimensions of coefficient of surface tension are...
(a) M¹L¹T^-2
(b) M¹L¹T¹
(c) M¹LT^-2
(d) M¹LT^-1
Answer: C

Question. A sample of gas is compressed to half its original volume while its temperature is held constant. If the average speed of the gas molecules was originally v, then their new average speed is...
(a) 4v
(b) v
(c) 2v
(d) v/2
Answer: B

Question. Generally, for a pure metal...
(a) C_p = C_v
(b) C_v = 3R/2
(c) C_p - C_v = R
(d) C_v - C_p = R
Answer: A

Question. Two 50 μF capacitors are connected in parallel. The equivalent capacitance of the combination is...
(a) 25 μF
(b) 50 μF
(c) 100 μF
(d) 200 μF
Answer: C

Question. Ferromagnetism is observe(d)..
(a) only in crystalline state
(b) only in amorphous solid state
(c) both in crystalline and amorphous state
(d) in any state of the substance
Answer: C

Question. The velocities of violet and red lights are Vv and Vr, respectively, then...
(a) V_v = V_r in glass
(b) V_v = V_r in vacuum
(c) V_v > V_r in glass
(d) V_v > V_r in vacuum
Answer: B

Question. 1 astronomical unit is equal to...
(a) 499 light seconds
(b) 149597 km
(c) 3 x 10¹⁰ km
(d) 3 x 10¹⁰ m
Answer: A

Question. The displacement of particles in a string stretched in the x-direction is represented by y. Among the following expressions for y, one that describes wave motion is...
(a) coskx sinωt
(b) k²x² - ω²t²
(c) cos²(kx + ωt)
(d) cos(k²x² - ω²t²)
Answer: A

Question. A boat which has a speed of 5 km/h 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/h is...
(a) 1
(b) 3
(c) 4
(d) √ 41
Answer: B

Question. If one mole of monoatomic gas (γ = 5/3) is mixed with one mole ofa diatomic gas (γ = 7/5), the value of γ for the mixture is...
(a) 1.40
(b) 1.50
(c) 1.53
(d) 3.07
Answer: B

Question. The ratio of the inertial mass to gravitational mass is...
(a) 0.5
(b) 0.2
(c) 1
(d) g/G
Answer: C

Question. On increasing the mass of a body suspended at the end of a spring kept vertically, its perio(d)..
(a) decreases
(b) increases
(c) does not change
(d) may increase or decrease
Answer: B