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. The relative strengths of four types of basic forces in nature is F_G : F_W : F_E : F_N = 10³⁸ : 10³⁶ : 10²⁵ :10⁰.
a) True
b) False

2. Units and Measurements - Quiz

1. Which of the following numbers has least number of significant figures?
a) 0.80760
b) 0.80200
c) 0.08076
d) 80.267

2. Suppose refractive index μ is given as
μ = A + $\frac{B}{\lambda^{2}}$
where A and B are constants and λ is wavelength, then dimensions of B are same as that of
a) Wavelength
b) Volume
c) Pressure
d) Area

3. Motion in a Straight Line - Quiz

1. A ball is thrown upwards with speed v from the top of a tower and it reaches the ground with speed 3v. What is the height of the tower?
a) $\frac{v^{2}}{g}$
b) $\frac{2v^{2}}{g}$
c) $\frac{4v^{2}}{g}$
d) $\frac{8v^{2}}{g}$

2. A train 110 m in length travels at 60 km/h . It passes a man who is walking at 6 km/h in the opposite direction in time 6 s.
a) True
b) False

4. Motion in a Plane - Quiz

1. Rain is falling vertically with a velocity of 25ms^-1. A woman rides a bicycle with a speed of 10 ms^-1 in the north to south direction. What is the direction (angle with vertical ) in which she should hold her umbrella to safe herself from rain ?
a) tan^-1(0.4)
b) tan^-1(1)
c) $tan^{-1}\left (\sqrt{3} \right )$
d) tan^-1(2.6)

2. The speed of a projectile at its maximum height is half of its initial speed. The angle of projection is
a) 60⁰
b) 15⁰
c) 30⁰
d) 45⁰

5. Laws of Motion - Quiz

1. One newton force is____________produces an acceleration of____________in a body of__________.
a) 1 m/s² ; mass 1 kg ; that much force which
b) That much force which ; 1 m/s² ; mass 1 kg
c) Both a and b
d) None of these

2. A 0.5 kg ball moving with a speed of 12 m/s strikes a hard wall at an angle of 30⁰ with the wall. It is reflected with the same speed and at the same angle, (figure). If the ball is in contact with the wall for 0.25 s, the average force acting on the wall is

a) 96 N
b) 48 N
c) 24 N
d) 12 N

6. Work, Energy and Power - Quiz

1. A toy gun uses a force constant K. Before being triggered in the upward direction, the spring, the spring is compressed by a distance x. If the mass of the shot is m, on being triggered it will go up to a maximum height of
a) $\frac{Kx^{2}}{mg}$
b) $\frac{x^{2}}{Kmg}$
c) $\frac{Kx^{2}}{2mg}$
d) $\frac{K^{2}x^{2}}{mg}$

2. A man of 50 kg mass is standing in a gravity free space at a height of 10 m above the floor. He throws a stone of 0.5 kg mass dwnwards with a speed 2 m/s. When the stone reaches the floor, the distance of the man above the floor will be
a) 9.9 m
b) 10.1 m
c) 10 m
d) 20 m

7. System of Particles and Rotational Motion - Quiz

1. O is the centre of an equilateral triangle ABC. F₁ , F₂ and F₃ are three forces acting along the sides AB, BC and AC as shown in the (figure). What should be the magnitude of F₃ so that the total torque about O is zero ?

a) (F₁ + F₂)/2
b) 2(F₁ + F₂)
c) (F₁ + F₂)
d) (F₁- F₂)

2. If a solid sphere of mass 1 kg and radius 0.1 m rolls without slipping at a uniform velocity of 1 ms^-1 along a straight line on a horizontal floor, the kinetic energy of the sphere is
a) (2/5)J
b) 1 J
c) (7/10)J
d) (7/5)J

8. Gravitation - Quiz

1. Both earth and moon are subject to the gravitational force of the sun, As observe from the sun, the orbit of the moon:
a) will be elliptical
b) will not be strictly elliptical because the total gravitational force on it is not central.
c) is not elliptical but will necessarily be a closed curve
d) deviates considerably from being elliptical due to influence of planets other then earth.

2. two satellites A and B go around a planet P in circular orbits having radiusR and 4R respectively . If the speed of the satellite is 3V, the speed of satellite B would be
a) 12 V
b) 6 V
c) 3V/2
d) 4V/3

9. Mechanical Properties of Solids - Quiz

1. The length of a metal wire is l when the tension is F and x l when the tension is y F. Then the natural length of the wire is
a) ((x-y)l/(x-1) )
b) (( y-x)l/(y-1))
c) ((x-y)l/(x+1))
d) ((y-x)l/(y+1))

2. A piece of material weighing 50.0 gram is coated with 6.3 gram of wax of sp. Gravity 0.9. If the coated piece weighs 16.3 gram in water, then the density of the material in g/c.c. is
a) 1.515
b) 2.112
c) 2.351
d) 4.613

10. Mechanical Properties of Fluids - Quiz

1. A 60 kg girl wearing high heel shoes balances on a single heel. The heel is circular with a diamter 1.5 cm. The pressure by the heel on the horizontal floor is 1.25 x 10⁴ Pa.
a) True
b) False

2. A ball is made of a material of density ρ where ρ _oil < ρ < ρ_water with ρ_oil and ρ_water representing the densities of oil and water, respectively. The oil and water are immiscible. If the above ball is in equilibrium in a mixture of this oil and water, which of the following pictures represents its equilibrium position?
a)

b)

c)

d)

11. Thermal Properties of Matter - Quiz

1. Hot water cools from 60⁰ to 50⁰ in the first 10 min and to 42⁰C in the next 10min. The temperature of the surrounding is
a) 5⁰C
b) 100C
c) 15⁰C
d) 20⁰C

2. The design of a physical instrument requires that , there be a constant difference in length of 10cm between an iron rod and a copper cylinder laid side by side at still temperatures. If α_Fe = $11 \times 10^{-6}/^{0}C$ and α_cu = $17 \times 10^{-6}/^{0}C$, their lengths may be
a) 28.3 cm, 18.3 cm
b) 23.8 cm, 10.9 cm
c) 23.9 cm, 10.9 cm
d) 27.5 cm, 14.5 cm

12. Thermodynamics - Quiz

1. Two cylinders of equal size are filled with equal amount of ideal diatomic gas at room temp. Both the cylinders are fitted with pistons. In cylinder A, the piston is free to move, while in cylinders B, the piston is fixed. When same amount of heat is supplied to both the cyclinders, temp. of gas in cylinders A rises by 30⁰K. What will be the rise in temp. of the gas in cylinder B?
a) 42^0K
b) 30⁰K
c) 20⁰K
d) 56⁰K

2. When a system is taken from state I to state f along the path iaf, it is found that Q = 50 Cal and W = 20 Cal, fig . Along the path ibf, Q = 36 Cal. W along the path ibf is

a) 14cal
b) 6 cal
c) 16 cal
d) 66 cal

13. Kinetic Theory - Quiz

1. 10 moles of an ideal monoatomic gas at 10⁰C are mixed with 20 moles of another monoatomic gas at 20⁰C. The the temp. of the mixture is
a) 15.5⁰C
b) 15⁰C
c) 16⁰C
d) 16.6⁰C

2. A gas is filled in a container at pressure P₀. If the mass of volumes is havled and their rms speed is doubled, then the resultant pressure would be
a) 2P₀
b) 4P₀
c) P₀/4
d) P₀/2

14. Oscillations - Quiz

1. In damped oscillations, the amplitude of oscillations is reduced to one-third of its initial value a0 at the end of 100 oscillations. When the oscillator completes 200 oscillations , its amplitude must be
a) a₀/2
b) a₀₉/6
c) a₀/9
d) a₀/4

2. Wave pulse on string shown in the figure is moving to the right without changing shape. Consider two particles at positions x₁ = 1.5 and x_@ = 2.5m. Their transverse velocities at the moment shown in the figure are along directions

a) positive y-axis and positive y-axis respectively
b) negative y-axis and positive y-axis respectively
c) positive y-axis and negative y-axis respectively
d) negative y-axis and negative y-axis respectively

15. Waves - Quiz

1. A student plots the frequency (n) of given length of a wire stretched by a gven force versus diameter (D) of the wire. The correct plot in (figure) 28 is
a)

b)

c)

d)

2. A car sounding its horn at 480Hz moves towards a high wall at speed of 20ms^-1, the frequency of the reflected sound heard by the man sitting in the car will be nearest to ; (speed of sound = 330m/s)
a) 480 Hz
b) 510 Hz
c) 540 Hz
d) 570Hz

16. Scalar and Vector - Quiz

1. The projection of a vector $\vec{r}$ = $3\hat{i} + \hat{j} + 2\hat{k}$ on the x-y plane has magnitude
a) 3
b) 4
c) $\sqrt{14}$
d) $\sqrt{10}$

2. Three vectors $\vec{A}, \vec{B}, \vec{C}$ satisfy the relation $\vec{A}.\vec{B}$ = 0 and $\vec{A}.\vec{C}$ = 0. The vector $\vec{A}$ is parallel to
a) $\vec{B}$
b) $\vec{C}$
c) $\vec{B}.\vec{C}$
d) $\vec{B} \times \vec{C}$

17. Conservation of momentum and Collision - Quiz

1. An object initially at rest explodes into three fragments A, B and C. The momentum of A is $p\hat{i}$ and that B is $\sqrt{3}p\hat{j}$ where p is a + ve number. The momentum of C will be
a) $(1+\sqrt{3})$p in a direction making angle 120⁰ with that of A.
b) $(1+\sqrt{3})$p in a direction making angle 150⁰ with that of B.
c) 2p in a direction making angle 150⁰ with that of A
d) 2p in a direction making angle 150⁰ with that of B.

2. Two particles A and B start moving due to their mutual interaction only. If at any time t , $\vec{a}_{A}$ and $\vec{a}_{B}$ and their respective accelerations, $\vec{v}_{A}$ and $\vec{v}_{B}$ are their respective velocities, and up to that time W_A and W_B are the work done on A and B , respectively, by the mutual force, m_A and m_B are their masses, respectively, then which of the following is always correct?
a) $\vec{v}_{A}+\vec{v}_{B}=0$
b) $m_{A}\vec{v}_{A}+m_{B}\vec{v}_{B}=0$
c) ${W}_{A}+{W}_{B}=0$
d) $\vec{a}_{A}+\vec{a}_{B}=0$

18. Rotational Dynamics - Quiz

1. A solid sphere rests on a horizontal surface. A horizontal impulse is applied at height h from centre. The sphere starts rolling just after the application of impulse. The ratio h/r will be

a) $\frac{1}{2}$
b) $\frac{2}{5}$
c) $\frac{1}{5}$
d) $\frac{2}{3}$

2. 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

19. Fluid Dynamics - Quiz

1. Air is streaming past a horizontal airplane wing such that its speed is 90 ms^-1 at the lower surface and 120 ms^-1 over the upper surface. If the wing is 10 m long and has an average width of 2 m, the difference of pressure on the two sides and the gross lift on the wing respectively, are (density of air = 1.3 kg m^-3)
a) 5 Pa, 900 N
b) 95 Pa, 900 N
c) 4095 Pa, 900 N
d) 4095 Pa, 81900 N

2. For the L-shaped vessel shown in the figure, determine the value of acceleration a so that pressure at point A becomes equal to p₀/2? (p₀ is the atmospheric pressure)

a) g
b) $\frac{g}{2}+\frac{p _{0}}{2\rho H}$
c) $\frac{p _{0}}{2\rho H}+g$
d) $\frac{3p _{0}}{2\rho H}+g$

Color

Physics [Class XI]

Class/Course - Class XI

Subject - Physics

Total Number of Question/s - 6437