#### First Mid Term Model Questions

11th Standard

Reg.No. :
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Physics

Time : 01:00:00 Hrs
Total Marks : 50
10 x 1 = 10
1. One of the combinations from the fundamental physical constants is ${{hc}\over{G}},$ The unit of this expression is

(a)

Kg2

(b)

m3

(c)

S-1

(d)

m

2. 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

3. What is the range of astronomical time scales to microscopic scales

(a)

1015S to 10-15S

(b)

109S to 10-18S

(c)

1018S to 10-22S

(d)

1011S to 10-16S

4. Which of the following Statement is true?

(a)

Velocity is a fundamental unit

(b)

Solar day = 24 hours.

(c)

1 Shake = 104s

(d)

mass is a derived unit

5. The mass of an iron sheet is 0.250 kg and volume of the sheet is 1.5m3 Then what is the density of the iron sheet? Express the result in SI unit system.

(a)

0.267kg m-3

(b)

0.167 kg m-3

(c)

0.255 kg m-3

(d)

0.285 kg m-3

6. The term used to mention study of macroscopic system to microscopic constituents is

(a)

unification

(b)

macrocosm

(c)

reductionism

(d)

microcosm

7. Which one of the following physical quantities cannot be represented by a scalar?

(a)

Mass

(b)

length

(c)

momentum

(d)

magnitude of acceleration

8. Two objects of masses m1 and m2 fall from the heights h1 and h2 respectively. The ratio of the magnitude of their momenta when they hit the ground is

(a)

$\sqrt { \frac { { h }_{ 1 } }{ { h }_{ 2 } } }$

(b)

$\sqrt { \frac { { { m }_{ 1 }h }_{ 1 } }{ { { m }_{ 2 }h }_{ 2 } } }$

(c)

$\frac { { m }_{ 1 } }{ { m }_{ 2 } } \sqrt { \frac { { h }_{ 1 } }{ { h }_{ 2 } } }$

(d)

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

9. If a particle executes uniform circular motion, choose the correct statement

(a)

The velocity and speed are constant

(b)

The acceleration and speed are constant.

(c)

The velocity and acceleration are constant.

(d)

The speed and magnitude of acceleration are constant.

10. A book is at rest on the table which exerts a normal force on the book. If this force is considered as reaction force, what is the action force according to Newton's third law?

(a)

Gravitational force exerted by Earth on the book

(b)

Gravitational force exerted by the book on Earth

(c)

Normal force exerted by the book on the table

(d)

None of the above

11. 5 x 2 = 10
12. Why is it convenient to express the distance of stars in terms of light year (or) parsec rather than in km?

13. Name three practical units to measure Area.

14. The Moon subtends an angle of 10 55' at the base line equal to the diameter of the earth. What is the distance of the Moon from the Earth? (Radius of the Earth is 6.4 x 106m)

15. Define a scalar. Give examples

16. Define degree.

17. 5 x 3 = 15
18. Calculate the number of times a human heart beats in the life of 100 years old man. Time of one heart beat = 0.8s.

19. What is meant by Collinear vector? Explain them.

20. Is the acceleration of a particle in circular motion not always towards the centre. Explain.

21. How long will a boy sitting near the window of a train travelling at 36 km h-1 see a train passing by in the opposite direction with a speed of 18 km h-1. The length of the slowmoving train is 90 m.

22. A rocket of mass 7000 kg is fired vertically. The acceleration of the rocket is 30 ms-2 and the exhaust speed is 700 m/s. find the amount of gas ejected per second.

23. 3 x 5 = 15
24. Write the rules for "Rounding off" with example

25. Write note on integration.

26. A monkey hangs on a tree. A hunter aims a gun at the monkey and fires the bullet with velocity Vo which makes angle $\alpha$o with horizontal direction. At the instant gun fires, monkey leaves the branch and falls straight down to escape from the bullet as shown in the figure. Will bullet hit the monkey or will the monkey escape the bullet? (ignore air resistance)