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

11th Standard

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Physics

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

25 x 1 = 25
1. The dimensional formula for gravitational constant G is

(a)

[ML3T-2]

(b)

[M-1L3T-2

(c)

[M-1L-3T-2

(d)

[ML-3T-2

2. The dimension of a quantity $hy \over c$ where h is the planck's constants, $\gamma$ is the frequency and c is the velocity of light are:

(a)

MT-1

(b)

MLT-1

(c)

MLT-2

(d)

ML2T2

3. Identify the pair of physical quantities having the same dimensions.

(a)

Light year and period of a pendulum

(b)

Angular momentum and torque

(c)

Energy and Modulus of elasticity

(d)

Torque and work

4. If E and B respectively, represent electric field and magnetic induction field, then the ratio $\frac{E}{B}$  has the dimensions of

(a)

angle

(b)

acceleration

(c)

velocity

(d)

displacement

5. Which two of the following five physical parameters have the same dimensions?
1.energy density
2.refractive index
3.dielectric constant
4.Young's modulus
5.magnetic field

(a)

1 and 4

(b)

1 and 5

(c)

2 and 4

(d)

3 and 5

6. TIle time dependence of a Physical quantity p is given by P=P0 exp(-at2) where a is a constant and t is the time. The constant a

(a)

is diemensionless

(b)

has dimensions[T-2]

(c)

has dimensions[T2]

(d)

has dimensions of P

7. An object is dropped in an unknown planet from height 50 m, it reaches the ground in 2 s . The acceleration due to gravity in this unknown planet is

(a)

g=20 ms-2

(b)

g=25 ms-2

(c)

g=15 ms-2

(d)

g=30 ms-2

8. The component of position vector $\overrightarrow { r }$ along x-axis will maximum value if

(a)

$\overrightarrow { r }$ is along the x - axis

(b)

$\overrightarrow { r }$ makes an angle of 45° with x - axis

(c)

$\overrightarrow { r }$  is along the y - axis

(d)

$\overrightarrow { r }$  is along - ve y - axis

9. A man should hold his umbrella with vertical, when rain falls vertically with velocity $\vec { { V }_{ R } }$ and man walks horizontally with velocity $\vec{{V}_{M}}$ is:

(a)

$tan^{-1}(\frac{\vec{V}_{M}}{\vec{V}_{R}})$

(b)

$tan^{-1}(\frac{\vec{V}_{R}}{\vec{V}_{M}})$

(c)

tan-1(VR)

(d)

tan-1(VM)

10. For a projectile, projected at an angle with the horizontal, the resultant velocity is:

(a)

$\sqrt{u^2+g^2t^2-2utg\quad sin\theta}$

(b)

$\sqrt{u^2+g^2t^2}$

(c)

$\sqrt{u^2-g^2t^2}$

(d)

$\sqrt{u^2+g^2t^2+2utg\quad sin\theta}$

11. If $\bar A$and $\bar B$ denotes the sides of a parallelogram whose area is $\frac{1}{1}\left| A \right|\left| B \right|$ the angle between $\bar A$and $\bar B$ is:

(a)

60°

(b)

450

(c)

30°

(d)

90°

12. What is the ratio of the angular speeds of the minute hand and second-hand of a clock?

(a)

1: 12

(b)

12: 1

(c)

1: 60

(d)

60: 1

13. A vector having unit magnitude is called________vector.

(a)

like

(b)

unlike

(c)

orthogonal

(d)

unit

14. Two masses m1 and m2 are experiencing the same force where m1 < m2.The ration of their acceleration $\frac { { a }_{ 1 } }{ { a }_{ 2 } }$is

(a)

1

(b)

less than 1

(c)

greater than 1

(d)

all the three cases

15. A body of mass 20 kg moving with a uniform velocity of 4 ms-1. Then the net force acting on a body is,

(a)

constant

(b)

increase

(c)

decrease

(d)

Zero

16. A body of mass M hits normally a rigid wall with velocity V and bounces back with the same velocity. The impulse experienced by the body is

(a)

MV

(b)

1.5 MV

(c)

2MV

(d)

zero

17. A wind-powered generator converts wind U(x) energy into electric energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed v, the electrical power output will be proportional to,

(a)

v

(b)

v2

(c)

v3

(d)

v4

18. A stationary particle explodes into two particles of masses m1and m2, which move in opposite directions with velocities v1 and v2. The ratio of their kinetic energies E1IE2 is

(a)

m2/m1

(b)

m1/m2

(c)

1

(d)

m1v2/m2v1

19. The area covered under force and displacement graph is

(a)

work done

(b)

acceleration

(c)

power

(d)

kinetic energy

20. The speed of a solid sphere after rolling down from rest without sliding on an inclined plane of vertical height his,

(a)

$\sqrt \frac{4}{3}gh$

(b)

$\sqrt \frac{10}{7}gh$

(c)

$\sqrt{2gh}$

(d)

$\sqrt \frac{1}{2}gh$

21. The mass of a body measures:

(a)

density

(b)

centre of mass

(c)

moment of inertia

(d)

coefficient of inertia

22. A car of mass 1000 kg negotiates a banked curve of radius 90 m on a frictionless road. If the banking angle is 45°, the speed of the car is

(a)

20ms-1

(b)

30ms-1

(c)

5ms-1

(d)

10ms-1

23. Two bodies of mass 1 kg and 3 kg have position vectors $\hat { i } +2\hat { j } +\hat { k }$ and respectively. The centre of mass of this system has a position vector.

(a)

$-2\hat { i } -\hat { j } +\hat { k }$.

(b)

$2\hat { i } -\hat { j } -2\hat { k }$.

(c)

$-\hat { i } +\hat { j } +\hat { k }$

(d)

$-2\hat { i } +2\hat { k }$.

24. Consider a system of two particles having masses m1 and m2 If the particle of mass ml is pushed towards the mass centre of particles through a distance d, by what distance would be particle of mass m2 move so all to keep the mass centre of particles at the original position?

(a)

$\frac { m_{ 1 } }{ { m }_{ 1 }+{ m }_{ 2 } }$d

(b)

$\frac { { m }_{ 1 } }{ { m }_{ 2 } }$d

(c)

d

(d)

$\frac { { m }_{ 2 } }{ { m }_{ 1 } }$d

25. If the mass and radius of the Earth are both doubled, then the acceleration due to gravity g'

(a)

remains same

(b)

${g\over 2}$

(c)

2g

(d)

4g