#### 11th Standard Physics English Medium Free Online Test One Mark Questions with Answer Key 2020 - Part Three

11th Standard

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Physics

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

Answer all the questions

25 x 1 = 25
1. How many light years make 1 parsec?

(a)

3.26

(b)

6.67

(c)

1.5

(d)

9.4

2. The density of a cube is measured by measuring its mass and length of its side. If the maximum error in the measurement of mass and length are 5% and 3%. respectively, the maximum error in the measurement of density is

(a)

9%

(b)

8%

(c)

14%

(d)

2%

3. Wllich pair do not have equal dimensions?

(a)

Energy and torque

(b)

Force and impulse

(c)

Angular momentum and Planck constant

(d)

Elastic modulus and pressure

4. During a projectile motion if the maximum height equals the horizontal range, then the angle of projection with the horizontal is:

(a)

tan-1(1)

(b)

tan-1(2)

(c)

tan-1(3)

(d)

tan-1(4)

5. In which direction of the motion of the particle does centripetal force act?

(a)

parallel

(b)

radial

(c)

tangential

(d)

right angle

6. According to parallelogram law of vector addition, the R:

(a)

$\sqrt {P^2+Q^2+2PQcos\theta}$

(b)

$\sqrt {P^2+Q^2-2PQcos\theta}$

(c)

$\sqrt {\frac{P^2}{Q^2}}$

(d)

$\sqrt {P^2cos^2\theta+Q^2sin^2\theta}$

7. Angle of inclination of the resultant when two v.ectors act at right angle to each other is:

(a)

$\frac {Q}{P}$

(b)

Q-P

(c)

Q + P

(d)

$\frac {P}{Q}$

8. Slope of displacement-time graph at any instant gives:

(a)

speed

(b)

acceleration

(c)

retardation

(d)

velocity

9. The velocity-time graph of a particle moving in a straight line is given in the figure. The acceleration of the particle at time t = 9s is

(a)

-5 ms-2

(b)

-3 ms-2

(c)

5 ms-2

(d)

Zero

10. A stone is thrown vertically upwards with certain initial speed. If another stone of the same mass is projected at angle of 30° with the horizontal with the same initial speed, the ratio of their potential energies at their highest points is

(a)

2:1

(b)

8:1

(c)

4:1

(d)

1:3

11. A stone falls freely under gravity. It covers distances h1,h2and h3 in the first 5 seconds, the next 5 seconds and the next 5 seconds respectively. The relation between h1,h2 and h3is

(a)

h2 = 3hl and h3 = 3h2

(b)

h1 = h2 = h3

(c)

h1 = 2h2 = h3

(d)

$h_1={h_2\over 3}={h_3\over 5}$

12. A particle starts its motion from rest under the action of a constant force. If the distance covered in first 10 seconds is S1 and that covered in the first 20 seconds is S2 ,then

(a)

$s_2=3s_1$

(b)

$s_2=4s_1$

(c)

$s_2=s_1$

(d)

$s_2=2s_1$

13. Two bodies A (of mass 1 kg) and B (of mass 3 kg) are dropped from heights of 16 m and 25 m, respectively. The ratio of the time taken by them to reach the ground is

(a)

4/5

(b)

5/4

(c)

12/5

(d)

5/12

14. A particle is thrown vertically upward. Its velocity at half of the height is 10 m/s, then the maximum height attained by it (g = 10 m/s2)

(a)

8m

(b)

6m

(c)

10m

(d)

16m

15. The water drop falls at regular intervals from a tap 5 m above the ground. The third drop is leaving the tap at instant the first drop touches the ground. How far above the ground is the second drop at that instant?

(a)

3.75m

(b)

4.00m

(c)

1.25m

(d)

2.50m

16. A car is moving along a straight road with a uniform acceleration. It passes through two points P and Q separated by a distance with. velocity 30 km/h and 40 km/h respectively. The velocity of the car midway between P and Q is

(a)

33.3km/h

(b)

20$\sqrt{2}$ km/h

(c)

25$\sqrt{2}$km/h

(d)

35km/h

17. Spreading smoke of incense stick is an example of

(a)

one dimensional motion

(b)

two dimensional motion

(c)

three dimensional motion

(d)

none

18. The distance travelled by a body, falling freely from rest in t = 1s, t = 2s and t = 3s are in the ratio of

(a)

1: 2: 3

(b)

1: 3: 5

(c)

1: 4: 9

(d)

9: 4: 1

19. Two projectiles of same mass and with same velocity are thrown at an angle of 60° and 30° with the horizontal then which of the following will remain same?

(a)

time of flight

(b)

range of projectile

(c)

maximum height reached

(d)

all the above

20. A heavy iron rod of weight W is having its one end on the ground and the other on the shoulder of a man. The rod makes an angle ፀ with the horizontal. What is the weight experienced by the man?

(a)

W sin ፀ

(b)

W cos ፀ

(c)

W

(d)

$\frac { W }{ 2 }$

21. The motion of a rocket is based on the principle of conservation of

(a)

Linear momentum

(b)

K.E

(c)

Mass

(d)

Angular momentum

22. Which of the following is not a scalar?

(a)

viscosity

(b)

surface tension

(c)

pressure

(d)

stress

23. When a uniform rod is heated, which of the following quantity of the rod will increase

(a)

mass

(b)

weight

(c)

center of mass

(d)

moment of inertia

24. A container has one mole of monoatomic ideal gas. Each molecule has f degrees of freedom. What is the ratio of $\gamma =\frac { { C }_{ p } }{ { C }_{ V } }$

(a)

f

(b)

$\frac{f}{2}$

(c)

$\frac{f}{f+2}$

(d)

$\frac{f+2}{f}$

25. For a particular tube, among six harmonic frequencies below 1000 Hz, only four harmonic frequencies are given: 300 Hz, 600 Hz, 750 Hz and 900 Hz. What are the two other frequencies missing from this list?.

(a)

100 Hz, 150 Hz

(b)

150 Hz, 450 Hz

(c)

450 Hz, 700 Hz

(d)

700 Hz, 800 Hz