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

11th Standard

Reg.No. :
•
•
•
•
•
•

Physics

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

25 x 1 = 25
1. The density of a material in CGS system of units is 4 g cm-3 . In a system of units in which unit of length is 10 em and unit of mass is 100 g, then the value of density of material will be

(a)

0.04

(b)

0.4

(c)

40

(d)

400

2. While measuring acceleration due to gravity, by a simple pendulum, a student makes a positive error of 1% in the length of the pendulum and a negative error , of 3% in the value of time period. The percentage error in the measurement of 'g' is

(a)

2%

(b)

4%

(c)

10%

(d)

7%

3. If 'am' and '$\triangle a_m$' are true value and mean absolute error respectively, then the magnitude of the quantity may lie between____________.

(a)

am + an to am - an

(b)

$a_m-\triangle a_m\ to\ a_m+\triangle a_m$

(c)

$2a_m\ to\ \triangle a_m$

(d)

0 to 2am

4. The unit of moment of force_______

(a)

Nm2

(b)

Nm

(c)

N

(d)

5. Odd one out ________

(a)

strain

(b)

refractive index

(c)

numbers

(d)

stress

6. Unit of impulse_____

(a)

NS2

(b)

NS

(c)

Nm

(d)

Kgms-2

7. Length cannot be measured by _______________

(a)

fermi

(b)

angstrom

(c)

parsec

(d)

debye

8. A ball is thrown vertically upward. It has a speed of 10 m/sec when it. has reached one half of its maximum height. How high does the ball rise?(Take g = 10 m/s2)

(a)

10m

(b)

5m

(c)

15m

(d)

20m

9. "norm" of the vector represents

(a)

only magnitude

(b)

only direction

(c)

both magnitude and direction

(d)

either magnitude or direction

10. If $\hat n$ is a unit vector along the direction of $\vec A$, the $\hat n$ is

(a)

$\vec AA$

(b)

n x A

(c)

$\frac{\vec A}{A}$

(d)

$\vec A|A|$

11. If $\vec p=m\vec V$ then the direction of $\vec P$ along

(a)

m

(b)

v

(c)

both (a) and (b)

(d)

neither m nor v

12. If $\vec A$ and $\vec B$ are two vectors, which are acting along x, y respectively, then $\vec A\times \vec B$ lies along

(a)

x

(b)

y

(c)

z

(d)

none

13. A bullet is dropped from some height, when another bullet is fired horizontally from the same height. They will hit the ground

(a)

depends upon mass of bullet

(b)

depends upon the observer

(c)

one after another

(d)

simultaneously

14. If a body moving in a circular path with uniform speed, then

(a)

the acceleration is directed towards its centre

(b)

velocity and acceleration are perpendicular to each other

(c)

speed of the body is constant but its velocity is varying.

(d)

all the above

15. Twelve forces each of magnitude 10N acting on' a body at an angle of 30° with other forces then their resultant is

(a)

10 N

(b)

120 N

(c)

$\frac{10}{\sqrt{3}}$

(d)

zero

16. If $\vec{r_1}$ and $\vec{r_2}$ are position vectors, then the displacement vector is

(a)

$\vec{r_1}\times \vec{r_2}$

(b)

$\vec{r_1}.\vec{r_2}$

(c)

$\vec{r_1}+\vec{r_2}$

(d)

$\vec{r_2}+\vec{r_1}$

17. A car starting from rest, accelerates at a constant rate x from sometimes after which it decelerates at a constant rate y to come to rest. If the total time elapsed is t, the maximum velocity attained by the car is given by

(a)

$\frac{xy}{x+y}t$

(b)

$\frac{xy}{x-y}t$

(c)

$\frac{x^2y^2}{x^2+y^2}t$

(d)

$\frac{x^2y^2}{x^2-y^2}t$

18. An object is moving in a straight line with uniform acceleration, the velocity-displacement relation is

(a)

V = u + 2as

(b)

$S=ut+\frac{1}{2}at^2$

(c)

V2 = u2 - 2as

(d)

V2 = u2 + 2as

19. In uniform circular motion

(a)

Speed changes but velocity constant

(b)

Velocity changes but speed constant

(c)

both speed and velocity are constant

(d)

both speed and velocity are variable

20. Which of the following graph represents the equation y = mx - C?

(a)

(b)

(c)

(d)

21. 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

22. 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)

$\frac { W }{ 2 }$

23. A block is kept on a frictionless inclined surface with angle of inclination ∝, The incline is given an acceleration a to keep the block stationary. Then a is equal to

(a)

g cosec ∝

(b)

g

(c)

$\frac { g }{ tan\quad \alpha }$

(d)

g tan ∝

24. The surface over which blocks are placed is smooth. What is the acceleration of each block in the given diagram?
F=27N

(a)

9 m/s2

(b)

3 ms-2

(c)

2 ms-2

(d)

0.33 ms-2

25. If the temperature and pressure of a gas is doubled the mean free path of the gas molecules

(a)

remains same

(b)

doubled

(c)

tripled

(d)