Question Bank for Physics in Class XI standard : Just Exam

1. Physical World - Quiz

1. Physics is a branch of __________which deals with the study of _______
a) nature and natural phenomena; science.
b) science ; nature and natural phenomena.
c) science; matter
d) none of these

2. The range of masses we study in Physics is
a) 10^-30kg to 10⁵⁵ kg
b) 10^-27 kg to 10⁵⁵ kg
c) 10^-27 kg to 10⁵⁵ kg
d) 10^-27 g to 10⁶⁰ g

2. Units and Measurements - Quiz

1. The area enclosed by a circle of diameter 1.06 m with correct number of significant figures is 0.882026 m².
a) True
b) False

2. 7.893 gram of a substance occupies a volume of 1.1 cm³. The density of substance with appropriate significant figures is
a) 7.175 g cm^-3
b) 7.2 g cm^-3
c) 7.18 g cm^-3
d) 7.1754 g cm^-3

3. Motion in a Straight Line - Quiz

1. If the position-time graph for the motion of a particle is a straight line parallel to position axis, then its velocity is_________.
a) finite
b) infinite
c) both a and b
d) none of these

2. A unit vector is a _____________and_________.
a) unitless ; dimensioness
b) dimensionless; unitless
c) both a and b
d) none of these

4. Motion in a Plane - Quiz

1. A ball is thrown upwards at an angle of 60⁰ to the horizontal. It falls on the ground at a distance of 90m. If the ball is thrown with the same initial velocity at an angle 30⁰, it will fall on the ground at a distance of
a) 120 m
b) 90 m
c) 60 m
d) 30 m

2. A particle is projected with a certain velocity at an angle α above the horizontal from the foot of an inclined plane of inclination 30⁰. If the plane strikes the plane normally, then α is equal to
a) $30^{0} + tan^{-1}\left (\frac{\sqrt{3}}{2} \right )$
b) 45⁰
c) 60⁰
d) 30⁰ + tan^-1(2$\sqrt{3}$)

5. Laws of Motion - Quiz

1. A man pulls himself up the 30⁰ incline by the method shown. If the combined mass of the man and cart is 100 kg. determine the acceleration of the cart idf the man exerts a pull of 250 N on the rope. Neglect all friction and the mass of the rope , pulleys, and wheels.

a) 4.5 ms^-2
b) 2.5 ms^-2
c) 3.5 ms^-2
d) 1.5 ms^-2

2. A block of mass m is at rest with respect to rough incline kept in elevator moving up with acceleration a. Which of following statements is correct?

a) The contact force between block and incline is parallel to the incline
b) The contact force between block and incline is of the magnitude m(g + a)
c) The contact force between block and incline is perpendicular to the incline
d) The contact force is magnitude ms cosθ

6. Work, Energy and Power - Quiz

1. If the potential energy of a gas molecule is U = M/r⁶ - N/r¹² , M and N being positive constants, then the potential energy at equilibrium must be
a) Zero
b) M²/ 4N
c) N²/4M
d) MN²/4

2. When linear momentum of a body is increased by 10%, increase in K.E. of the body is_________.
a) 20%
b) 21%
c) Both a and b
d) None of these

7. System of Particles and Rotational Motion - Quiz

1. A cyclinder of radius R and mass M rolls without slipping down a plane inclined at an angle θ. Coeff. Of friction between the cyclinder and the plane is μ. For what maximum inclination θ, the cyclinder rolls without slipping?
a) tan^-1 μ
b) tan^-1 (3μ)
c) tan^-1 2 μ
d) tan^-1 3/2 μ

2. A uniform rod of length l and mass m is free to rotate in a vertical plane about A as shown in (figure). The rod initially in horizontal position is released. The initial angular acceleration of the rod is

a) 3g/2l
b) 3g/l
c) g/2l
d) 2g/l

8. Gravitation - Quiz

1. The magnitude of external force required to produce unit acceleration in the body is equal to ________ of the body.
a) inertial mass
b) mass
c) weight
d) none of these

2. A satellite moves around the earth in a circular orbit will speed v. If m is the mass of the satellite, its total energy is
a) $-\frac{1}{2}mv^{1}$
b) $\frac{1}{2}mv^{1}$
c) $\frac{3}{2}mv^{1}$
d) $\frac{1}{4}mv^{1}$

9. Mechanical Properties of Solids - Quiz

1. A metal rod has a length of 100 cm and across-section of 1.0 cm². By raising its temperature from 0⁰C to 100⁰C and holding it so that it is not permitted to expand or bend, the force developed is (Given Y = 10¹² dyne cm^-2 and α = 10^-5 ⁰C^-1)
a) 10⁸ dyne
b) 10⁹ dyne
c) 10¹⁰ dyne
d) 10¹⁴ dyne

2. The length of a wire is increased by 1 mm on the application of a given load. In a wire of the same material, but of length and radius twice that of the first, on application of the same load, extension is
a) 0.25 mm
b) 0.5mm
c) 2 mm
d) 4 mm

10. Mechanical Properties of Fluids - Quiz

1. When water flows at a rate Q through a tube of radius r placed horizontally, a pressure difference p develops across the ends of the tube. If the radius of the tube is doubled and the rate of flow halved, the pressure difference will be
a) 80 p
b) p
c) p/8
d) p/32

2. Water flows through a vertical tube of variable cross-section. The area of cross-section at A and B are 6 and 3 mm² respectively. If 12 cc of water enters per second through A, find the pressure difference P - P_B( g = 10 m/s²). The separation between the cross-sections at A and B is 100 cm.

a) 1.6 x 10⁵ dyne/cm²
b) 2.29 x 10⁵ dyne/cm²
c) 5.9 x 10⁵ dyne/cm²
d) 3.9 x 10⁵ dyne/cm²

11. Thermal Properties of Matter - Quiz

1. Fig. shows the graphs of elongation versus temperature for two different metals. If these metals are employed to form a straight bimetallic strip of thickness 6 cm and heated, it bends in the form of an arc, the radius of curvature changing with temperature approximately as shown in the figure. The linear expansivities of the two metals are

a) $24 \times 10^{-6}/^{0}C \ and \ 12 \times 10^{-6}/^{0}C$
b) $20 \times 10^{-6}/^{0}C \ and \ 10 \times 10^{-6}/^{0}C$
c) $18 \times 10^{-6}/^{0}C \ and \ 9 \times 10^{-6}/^{0}C$
d) $16 \times 10^{-6}/^{0}C \ and \ 8 \times 10^{-6}/^{0}C$

2. If the radius of a star is R and it acts as a black body, what would be the temperature of the star, in which the rate of energy production in Q?
a) Q/4 π R² σ
b) (Q/4 π R² σ)^-1/2
c) (4 π R² Q/σ)^1/4
d) (Q/4 π R² σ)^1/4

12. Thermodynamics - Quiz

1. Work done on the gas in taking it from D to A , in fig. is

a) +414 R
b) -690 R
c) +690 R
d) -414 R

2. An ideal gas heat engine operates in carnot cycle between 227⁰C and 127⁰C. It absorbs 6× 10⁴ cals of heat at higher temperature. Amount of heat converted to work is:
a) 4.8 × 10⁴ cals
b) 2.4 × 10⁴ cals
c) 1.2 × 10⁴ cals
d) 6 × 10⁴ cals

13. Kinetic Theory - Quiz

1. The temperature of an ideal gas is increased from 120K to 480K. The rms velocity of gas molecules becomes
a) half
b) double
c) quadrupled
d) cannot say

2. The molar heat capacity varies as C = C_v + βV. Then the equation of the process for an ideal gas is given as
a) $T^{\frac{\beta}{RV}}$ = constant
b) $V^{\frac{\beta T}{R}}$ = constant
c) $T^{\frac{R}{\beta V}}$ = constant
d) $V^{\frac{R}{\beta T}}$ = constant

14. Oscillations - Quiz

1. In linear SHM, a particle moves _______ near the mean position and _____ near the extreme position.
a) faster ; slower
b) slower ; faster
c) Both a and b
d) none of these

2. A tuning fork has a frequency of 256. Distance travelled by sound emitted during the time it makes 16 vibrations is (v = 332 m/s)
a) 256 m
b) 332m
c) 20.7m
d) 256 × 16 m

15. Waves - Quiz

1. the ratio of intensities between two coherent sound sources is 4:1. The difference of loudness in decibels (dB) maximum and minimum intensities when they interference in space is
a) 10log(2)
b) 20 log(3)
c) 10 log(3)
d) 20 log(2)

2. In the fundamental mode of vibration of sonometer wire, nodes are formed
a) One at each wedge
b) One at the peg only
c) One at the pulley only
d) One at the centre of sonometer wire

16. Scalar and Vector - Quiz

1. Two forces , each equal to F, act as shown in Fig. Their resultant is

a) F/2
b) F
c) $\sqrt{3}F$
d) $\sqrt{5}F$

2. The resultant of three vectors 1,2, and 3 units whose directions are those of the sides of an equilateral triangle is at an angle of
a) 30⁰ with the first vector
b) 15⁰ with the first vector
c) 100⁰ with the first vector
d) 150⁰ with the first vector

17. Conservation of momentum and Collision - Quiz

1. A ball is let fall from a height h₀. There are n collisions with the earth. If the velocity of rebound after n collisions is v_n and the ball rises to a height h_n, then coefficient of restitution e is given by
a) $e^{n}=\sqrt{\frac{h_{n}}{h_{0}}}$
b) $e^{n}=\sqrt{\frac{h_{0}}{h_{n}}}$
c) $ne=\sqrt{\frac{h_{n}}{h_{0}}}$
d) $\sqrt{ne}=\sqrt{\frac{h_{n}}{h_{0}}}$

2. After a totally inelastic collision, two objects of the same mass and same initial speeds are found to move together at half of their initial speeds. The angle between the initial velocities of the objects is
a) 120⁰
b) 60⁰
c) 150⁰
d) 45⁰

18. Rotational Dynamics - Quiz

1. In the figure shown, the instantaneous speed of end A of the rod is v to the left. The angular velocity of the rod of length L must be

a) $\frac{v}{2L}$
b) $\frac{v}{L}$
c) $\frac{v\sqrt{3}}{2L}$
d) none of these

2. Two bodies with moments of inertia I₁ and I₂ (I₁ > I₂) have equal angular momenta. If their kinetic energies of rotation are E₁ and E₂ , respectively, then
a) E₁ = E₂
b) E₁ < E₂
c) E₁ > E₂
d) E₁ ≥E₂

19. Fluid Dynamics - Quiz

1. A non-uniform cylinder of mass m, length l and radius r is having its centre of mass at a distance l/4 from the centre and lying on the axis of the cylinder. The cylinder is kept in a liquid of uniform density ρ. The moment of inertia of the rod about the centre of mass is I. The angular acceleration of point A relative to point B just after the rod is released from the position as shown in the figure is

a) $\frac{\pi \rho gl^{2}r^{2}}{I}$
b) $\frac{\pi \rho gl^{2}r^{2}}{4I}$
c) $\frac{\pi \rho gl^{2}r^{2}}{2I}$
d) $\frac{3\pi \rho gl^{2}r^{2}}{4I}$

2. Equal masses of three liquids are kept in three identical cylindrical vessels A, B and C. Their densities are ρ_A , ρ_B and ρ_C with ρ_A < ρ_B < ρ_C. The force on the base will be
a) maximum in vessel A
b) maximum in vessel B
c) maximum in vessel C
d) same in all the three vessels

Color

Physics [Class XI]

Class/Course - Class XI

Subject - Physics

Total Number of Question/s - 6437