#### 11th Standard Physics English Medium Free Online Test 1 Mark Questions 2020 - Part Nine

11th Standard

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Physics

Time : 00:25:00 Hrs
Total Marks : 25

25 x 1 = 25
1. A student measures the distance traversed in free fall of a body, initially at rest, in a given time, He uses this data to estimate g, the acceleration due to gravity, If the maximum percentage errors in measurement of the distance and the time are e1 and e2 respectively, the percentage error in the estimation of g is

(a)

e2-e1

(b)

e1+2e2

(c)

e1+e2

(d)

e1-2e2

2. If one object is dropped vertically downward and another object is thrown horizontally from the same height, then the ratio of vertical distance covered by both objects at any instant t is

(a)

1

(b)

2

(c)

4

(d)

0.5

3. When a body moves once circular path, the:

(a)

magnitude of velocity changes and its direction remain constant

(b)

magnitude of velocity remains constant and its direction changes continuously

(c)

magnitude of velocity remains constant and direction remains constant

(d)

magnitude of velocity and direction changes continuously

4. In the absence of air resistance, horizontal velocity of the projectile is

(a)

always negative

(b)

equal to 'g'

(c)

directly proportional to g

(d)

a constant

5. With increase of temperature, the frictional force acting between two surfaces:

(a)

increases

(b)

remains the same

(c)

decreases

(d)

becomes zero

6. A bullet hits and gets embedded in a solid block resting on a horizontal frictionless table. Which of the following is conserved?

(a)

Momentum and kinetic energy

(b)

kinetic energy alone

(c)

Momentum alone

(d)

potential energy alone

7. A mass m moving horizontally (along the x-axis) with velocity v collides and sticks to a mass of 3m moving vertically upward (along the y-axis) with velocity 2v. The final velocity of the combination is

(a)

$\frac{3}{2}v\hat i+\frac{1}{4}v\hat j$

(b)

$\frac{1}{4}v\hat i+\frac{3}{2}v\hat j$

(c)

$\frac{1}{3}v\hat i+\frac{2}{3}v\hat j$

(d)

$\frac{2}{3}v\hat i+\frac{1}{3}v\hat j$

8. Three particles, each of mass m gram, are situated at the vertices of an equilateral triangle ABC of side I cm (as shown in the figure). The moment of inertia of the system about a line AX perpendicular to AB and in the plane of ABC, in gram-cm2 units will be

(a)

$\frac { 3 }{ 4 }$ml2

(b)

2 ml2

(c)

$\frac { 5 }{ 4 }$ml2

(d)

$\frac { 3 }{ 2 }$ml2

9. A gramophone record is revolving with an angular velocity$\omega$ . A coin is placed at a distancc r from the centre of the record. The static coefficient of friction is $\mu$ . The coin will revolve with the record if

(a)

$r=\mu g \omega^2$

(b)

$r=<{\omega^2\over \mu g }$

(c)

$r=\le{\mu g\over \omega^2}$

(d)

$r=\ge{\mu g\over \omega^2}$

10. A mass is whirled in a circular path with constant angular velocity and its angular momentum is L. while the string is now halved keeping the angular velocity the same, the angular momentum is

(a)

$\frac { L }{ 4 }$

(b)

$\frac { L }{ 2 }$

(c)

L

(d)

2L

11. The sum of moments of masses of all the particles in a system about the center of mass is

(a)

minimum

(b)

maximum

(c)

zero

(d)

infinity

12. The direction of torque acts

(a)

along $\overrightarrow {F}$

(b)

along $\overrightarrow {r}$&$\overrightarrow {F}$

(c)

Perpenticular to $\overrightarrow {r}$

(d)

Perpenticular to both $\overrightarrow {r}$ and $\overrightarrow {F}$

13. If two soap bubbles of different radii are connected by a tube, then

(a)

air flows from bigger to the smaller bubble till the sizes become equal

(b)

air flows from bigger bubble to the smaller bubble till the size are interchanged

(c)

air flows from the smaller bubble to the bigger

(d)

there is number flow of air

14. A piece of wood is taken deep inside a long column of water & released it will move up.

(a)

with a constant upward acceleration

(b)

with decreasing upward acceleration

(c)

with a deceleration

(d)

there will be uniform velocity

15. The period of revolution of planet A around the Sun is 8 times that of B. The distance of A from the Sun is how many times greater than that of B from the Sun.

(a)

2

(b)

3

(c)

4

(d)

5

16. A certain number of spherical drops of a liquid of radius R coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then

(a)

energy = 4 V T $\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right)$is released

(b)

energy = 3 V T $\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right)$is absorbed

(c)

energy = 3 V T $\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right)$is released

(d)

energy is neither released nor absorbed

17. Substances that elongate considerably and undergo plastic deformation before they break are known as

(a)

brittle substances

(b)

breakable substances

(c)

ductile substances

(d)

elastic substances

18. The mass of 1 litre of helium under a pressure of 2 atm and at a temperature of 27°C is

(a)

0.16 g

(b)

0.32g

(c)

0.48g

(d)

0.64 g

19. For an ideal gas the interparticle interaction is ___________

(a)

attractive

(b)

repulsive

(c)

very large

(d)

zero

20. If the absolute temperature of a gas is increased 3 times the rms velocity of the molecules will be _________.

(a)

3 times

(b)

9 times

(c)

$\sqrt 3$ times

(d)

$\sqrt 6$ times

21. Pressure exerted by a gas is _______.

(a)

independent of the density of the gas

(b)

inversely proportional to the density of the gas

(c)

directly proportional to the density of the gas

(d)

directly proportional to the square of the density of the gas

22. The average energy of a molecules of a mono atomic gas at temperature T is (K = Boltzmann constant)

(a)

$\frac{1}{2}$kT

(b)

kT

(c)

$\frac{3}{2}$kT

(d)

$\frac{5}{2}$kT

23. The rms speed of the particles of fume of mass 5 x 10-17 kg executing Brownian motion in air at STP is  _________.

(a)

1.5 ms-1

(b)

3.0 ms-1

(c)

1.5 cms-1

(d)

3.0 cms-1

24. A particle, moving ·along the x-axis, executes simple harmonic motion when the force acting on it is given by (A and k are positive constants.) ________.

(a)

- Akx

(b)

A cos(kx)

(c)

A exp(-kx)

(d)

Akx

25. Two simple pendulums of lengths 0.5m and 2.0m respectively are given small linear displacement in one direction at the same time. They will again be in phase when the pendulum of shorter length has completed _______ oscillations.

(a)

5

(b)

3

(c)

1

(d)

2