Question Bank for Physics in Class XI standard : Just Exam

1. Physical World - Quiz

1. 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. Einstein was awarded Nobel Prize in Physics for
a) Theory of relativity
b) Law f gravitation
c) Uncertainty Principle
d) Photo electricity

2. Units and Measurements - Quiz

1. A student uses a simple pendulum of exactly 1 m length to determine g, the acceleration due to gravity. He uses a stop watch with the least count of 1 sec for this and records 40 seconds for 20 oscillations. For this observation, which of the following statement (s) (are) true?
a) Error ΔT in measuring T, the time period , is 0.05 seconds
b) Error ΔT in measuring T, the time period, is 1 second
c) Percentage error in the determination of g is 5%
d) Perecentage error in the determination of g is 2.5%

2. If Planck constant (h) and speed of light in vacuum (c ) are taken as two fundamental quantities, which one of the following can, in addition, be taken to express length, mass and time in terms of the three chosen fundamental quantities?
a) Mass of electron (m_e)
b) Universal gravitational constant ( G)
c) Charge of electron (e )
d) Mass of proton (m_p)

3. Motion in a Straight Line - Quiz

1. A body is projected upwards with a velocity u. It passes through a certain point above the ground after t₁. The time after which the body passes through the same point during the return journey is
a) $\left (\frac{u}{g} - t_{1}^{2} \right )$
b) $2\left (\frac{u}{g} - t_{1} \right )$
c) $3\left (\frac{u^{2}}{g} - t_{1} \right )$
d) $3\left (\frac{u^{2}}{g^{2}} - t_{1} \right )$

2. Two forces 5 kg wt and 10 kg wt are acting with an inclination of 120⁰ between them. The angle which the resultant makes with 10 kg wt is 30⁰
a) True
b) False

4. Motion in a Plane - Quiz

1. The horizontal range is same whether the angle of projection is α or β, where α+β = ______
a) 0⁰
b) 90⁰
c) 180⁰
d) none of these

2. A ball is projected from the ground at angle θ with the horizontal . After 1s it moving at angle 45⁰ with the horizontal and after 2s it is moving horizontally. What is the velocity of projection of the ball?
a) 10$\sqrt{3}$ ms^-1
b) 20$\sqrt{3}$ ms^-1
c) 10$\sqrt{5}$ ms^-1
d) 20$\sqrt{2}$ ms^-1

5. Laws of Motion - Quiz

1. An insect crawls up a hemispherical surface very slowly, (figure). The coefficient of friction between the insect and the surface is 1/3. If the line joining the centre centre of the hemispherical surface to the insect makes an angle α with vertical, the max.possible value of α is given by

a) cot α = 3
b) sec α = 3
c) cosec α = 3
d) None

2. A trolley T of mass 5kg on a horizontal smooth surface is pulled by a load of 2kg through a uniform rope ABC of length 2m and mass 1kg. As the load falls from BC = 0 to BC = 2m, its acceleration (in ms^-2) changes from

a) $\frac{20}{6} to \frac{30}{6}$
b) $\frac{20}{8} to \frac{30}{8}$
c) $\frac{20}{5} to \frac{30}{6}$
d) None of these

6. Work, Energy and Power - Quiz

1. A block of mass 10 kg is moving in x-direction with a constant speed of 10 m/s. It is subjected to a retarding force F = 0.1 x joule/metre during its travel from x = 20 m to x =30 m. Its final K.E. will be
a) 475 J
b) 450 J
c) 275 J
d) 250 J

2. The kinetic energy K of a particle moving along a circle of radius R depends upon the distance s as K = as². The force acting on the particle is
a) $2a\frac{s^{2}}{R}$
b) $2as\left [1 + \frac{s^{2}}{R} \right ]^{1/2}$
c) 2as
d) 2a

7. System of Particles and Rotational Motion - Quiz

1. A grindstone of moment of interia 6 kg m² is found to have a speed of 150 rpm, 10 sec. after starting from rest. Torque applied is
a) 6 л Ns
b) 3 π Ns
c) 9 π Ns
d) 12 π Ns

2. A boy is pushing a ring of mass 2 kg and radius 0.5 m with a stick as shown in the (figure)

The stick applies a force of 2 N on the ring and rolls it without slipping with an acceleration of 0.3 m/s².
The coefficient of friction between the ground and the ring is large enough that rolling always occurs and coefficient of friction between the stick and the ring is (P/10). The value of P is
a) 3
b) 4
c) 5
d) 6

8. Gravitation - Quiz

1. The density of a newly discovered planet is twice that of earth . The acceleration due to the gravity the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is R. The radius of the planet would be
a) 2R
b) 4R
c) R/4
d) R/2

2. Figure shows a planet in an elliptical orbit around the sun S. Whare is the kinetic energy of the planet maximum?

a) P₁
b) P₂
c) P₃
d) P₄

9. Mechanical Properties of Solids - Quiz

1. A brass bar of length 0.2 m and cross-sectional are 1 cm² is compressed with a load of 5 kg increase in elastic of brass is 2.4 x 10^-3 J.
a) True
b) False

2. Two wires of the same length and same material but radii in the ratio of 1:2 are stretched by unequal forces to produce equal elongation. The ratio of the two forces is
a) 1:1
b) 1:2
c) 1:3
d) 1:4

10. Mechanical Properties of Fluids - Quiz

1. A ball whose density is 0.4 x 10³ falls into water from a height of 9 cm. To what depth does the ball sink?
a) 4.5 cm
b) 6.0 cm
c) 7.5 cm
d) 800

2. The velocity of liquid flow, upto which its flow is streamlined and above which its flow becomes turbulent is called __________.
a) Critical velocity
b) velocity
c) Both a and b
d) None of these

11. Thermal Properties of Matter - Quiz

1. Heat is required to change 1kg of ice at = 20⁰C into steam Q₁ is the heat needed to warm the ice from -20⁰C to 0⁰C, Q₂ is the heat needed to melt the iice, Q₃ is the heat needed to warm the water from 0⁰C to 100⁰C and Q₁ is the heat needed to vapourize the water. Then
a) $Q_{4} > Q_{3} > Q_{2} > Q_{1}$
b) $Q_{4} > Q_{3} > Q_{1} > Q_{2}$
c) $Q_{4} > Q_{2} > Q_{3} > Q_{1}$
d) $Q_{4} > Q_{2} > Q_{1} > Q_{3}$

2. A uniform metal rod is used as a bar pendulum. If the room temperature rises by 10⁰C, and the coefficient of linear expansion of the metal of the rod is 2 x 10^-6per⁰C. the period of the pendulum will have percentage increase of
a) -2 x 10^-3
b) -1 x 10^-3
c) 2 x 10^-3
d) 1 x 10^-3

12. Thermodynamics - Quiz

1. Net work done on the gas in cycle ABCDA in fig. is

a) 276 R
b) 1076 R
c) 1904 R
d) zero

2. A thermically insulted vessel contains an ideal gas of molecular mass M and ratio of specific heats γ. It is moving with speed υ and is suddenly brought to rest. Assuming no heat is lost to the surroundings, its temperature increased by
a) (γ-1)mυ²K/2γR
b) γMυ²K/2R
c) (γ-1)Mυ²K/2R
d) (gamma;-1)Mupsilon;K/2(gamma;+1)R

13. Kinetic Theory - Quiz

1. All curves foe real gases approach the ideal gas behavior at
a) low pressure only
b) high temperature only
c) low pressure and high temperature
d) high pressures and low temperatures

2. Temperature remaining constant, the pressure of gas is decreasedby 20%. The percentage change in volume is
a) increased by 20%
b) decreased by 20%
c) increased by 25%
d) decreased by 25%

14. Oscillations - Quiz

1. A particle executes simple harmonic motion between x- -A and x= +A. The time taken for it to go from 0 to A/2 is T₁, and to go from A/2 to A is T₂ . Then
a) T₁ < T₂
b) T₁ > T₂
c) T₁ = T₂
d) T₁ = 2T₂

2. A sonometer wire resonates with a given tuning fork forming standing waves with five antinodes between the two bridges, when this mass of 9kg is suspended from the wire. When this mass is replaced by mass M, the wire resonates with the same tuning fork forming three antinodes for the same position of the bridges. The value of M is
a) 25 kg
b) 5 kg
c) 12.5 kg
d) 1/25 kg

15. Waves - Quiz

1. A sonometer wire resonates with a given tuning fork forming 5 antinodes when a mass 9kg is suspended from the wire. When this time is replaced by a mass m, the wire resonates with the same tuning fork forming three antinodes for the same positions of the bridges. The value of M is
a) 25 kg
b) 5 kg
c) 12.5 kg
d) (1/25)kg

2. A train moving at a speed of 220ms^-1 towards a stationary object, emits a sound of frequency 1000Hz. Some of the sound reaching the object gets reflected back to the train as echo. The frequency of the echo as detected by a person in the train is:(speed of sound in air is 330ms^-1
a) 3500 Hz
b) 4000Hz
c) 5000Hz
d) 3000Hz

16. Scalar and Vector - Quiz

1. If $\vec{b}$ = $3\hat{i}+ 4\hat{j}$ and $\vec{a}$ = $\hat{i}$ - $\hat{j}$, the vector having the same magnitude as that of $\vec{b}$ and parallel to $\vec{a}$ is
a) $\frac{5}{\sqrt{2}}\left (\hat{i} - \hat{j} \right )$
b) $\frac{5}{\sqrt{2}}\left (\hat{i}+ \hat{j} \right )$
c) $5\left (\hat{i} - \hat{j} \right )$
d) $5\left (\hat{i} + \hat{j} \right )$

2. The sum of the magnitudes of two forces acting at a point is 16N. The resultant of these forces is perpendicular to the smaller force and has a magnitude of 8N. If the smaller force is of magnitude x, then the value of x is
a) 2N
b) 4N
c) 6N
d) 7N

17. Conservation of momentum and Collision - Quiz

1. Two blocks of masses 6 kg and 4 kg are attached to the ends of a massless string passing over a smooth fixed pulley. If the system is released, the acceleration of the centre of mass of the system will be
a) g, vertically downwards
b) g/5, vertically downwards
c) g/25, vertically downwards
d) zero

2. A ball released from a height h₀ above a horizontal surface rebounds to a height h₁ after one bounce. The graph that relates h₀ to h₁ is shown in Figure. If the ball ( of the mass m) was dropped from an initial height h and made three bounces, the kinetic energy of the ball immediately after the third impact with the surface was

a) (0.8)³ mgh
b) (0.8)² mgh
c) 0.8 mg (h/3)
d) [1-(0.8)³] mgh

18. Rotational Dynamics - Quiz

1. A uniform disc of radius R lies in the x-y plane, with its centre at origin. Its moment of inertia about z-axis is equal to its moment of inertia about line y = x+c.The value of c will be
a) $-\frac{R}{2}$
b) $\pm \frac{R}{\sqrt{2}}$
c) $+\frac{R}{4}$
d) -R

2. Two painters are working from a wooden board 5 cm long suspended from the top of a building by two ropes attached to the ends of the plank. Either rope can withstand a maximum tension of 1040 N. Painter A of mass 80 kg is working at a distance of 1 m from one end. Painter B of mass 60 kg is working at a distance of x m from the centre of mass of the board on the other side. Take mass of the board as 20 kg and g = 10 m/s². The range of x so that both the painters can work safely is
a) $\frac{1}{3}< x < \frac{11}{6}$
b) $0< x < \frac{11}{6}$
c) 0 < x < 2
d) $\frac{1}{3}< x < 2$

19. Fluid Dynamics - Quiz

1. Three identical vessels A, B and C contain same quantity of liquid. In each vessel balls of different densities but same masses are placed. In vessel A, the ball is partly submerged; in vessel B, the ball is completely submerged but floating and in vessel C, the ball has sunk to the base. If F_A , F_B and F_C are the total forces acting on the base of vessels A, B and C, respectively, then

a) F_A = F_B = F_C
b) F_A < F_B < F_C
c) F_A = F_B < F_C
d) F_A < F_B < F_C

2. A pressure meter attached to a closed water tap reads 1.5 × 10⁵ Pa. When the tap is opened, the velocity of flow of water is 10 ms^-1 and the reading of the pressure meter is
a) 1.5 × 10⁵ Pa
b) 3 × 10⁵ Pa
c) 0.5 × 10⁵ Pa
d) 10⁵ Pa

Color

Physics [Class XI]

Class/Course - Class XI

Subject - Physics

Total Number of Question/s - 6437