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