#### Model Question Paper - I

11th Standard

Reg.No. :
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Physics

Time : 03:00:00 Hrs
Total Marks : 100

Part A

20 x 1 = 20
1. If the error in the measurement of radius is 2%, then the error in the determination of volume of the sphere will be

(a)

8%

(b)

2%

(c)

4%

(d)

6%

2. If the length and time period of an oscillating pendulum have errors of 1% and 3% respectively then the error in measurement of acceleration due to gravity is

(a)

4%

(b)

5%

(c)

6%

(d)

7%

3. 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

4. If the force is proportional to square of velocity, then the dimension of proportionality constant is

(a)

[MLT0]

(b)

[MLT-1]

(c)

[MLT-2T]

(d)

[MLT-1T0]

5. A projectile is thrown in the upward direction making an angle of ${ 60 }^{ 0 }$ with the horizontal direction with a velocity of 147 m/s.Then,the time after which its inclination with the horizontal is ${ 45 }^{ 0 }$,is

(a)

15 s

(b)

10.98 s

(c)

5.49 s

(d)

2.745 s

6. A ship A is moving Westwards with a speed of 10 km/h and ship B 100 km South of A, is moving Northwards with a speed of 10 km/h.The time after which the distance between them becomes shortest,is

(a)

0h

(b)

5h

(c)

$5\sqrt { 2 }$h

(d)

$10\sqrt { 2 }$

7. Three vector A, B and C satisfly the relation A.B = 0 and A .C = 0.  Then the vector A is paralell to

(a)

B

(b)

C

(c)

.C

(d)

$\times$ C

8. What is the dot product of two vectors of magnitude 3 and 5, if angle between them is 60o?

(a)

5.2

(b)

7.5

(c)

8.4

(d)

8.6

9. A ground to ground projectile is at point A at t = $\frac{T}{3}$, is at point B at t = $\frac{5T}{6}$ and reaches the ground at t = T. The difference in heights between points A and B is

(a)

$\frac { g{ T }^{ 2 } }{ 6 }$

(b)

$\frac { g{ T }^{ 2 } }{ 12 }$

(c)

$\frac { g{ T }^{ 2 } }{ 18 }$

(d)

$\frac { g{ T }^{ 2 } }{ 24 }$

10. A cart is moving horizontally along a straight line with a constant speed of 30 m/s. A projectile is to be fired from the moving cart in such a way that it will return to the cart (at the same point on cart) after the cart has moved 80 m. At what velocity (relative to the cart) must be projectile be fired ? (Take g = 10 m/s2 )

(a)

10 m/s

(b)

$\frac{20}{3}$ m/s

(c)

$\frac{40}{3}$ m/s

(d)

$\frac{80}{3}$ m/s

11. A cart is moving horizontally along a straight line with constant speed 30 m/s. A projectile is to be fired from the moving cart in such a way that it will return to the cart after the cart has moved 80 m. At what speed (Relative to the cart) must the projectile be fired ? (Take g = 10 m/s2 )

(a)

10 ms-1

(b)

10 $\sqrt{8}$ ms-1

(c)

$\frac{40}{3}$ ms-1

(d)

None of the above

12. A particle of mass m is projected with a velocity v at an angle of 60° with horizontal. When the particle is at its maximum height. The magnitude of its angler momentum about the point of projection is

(a)

Zero

(b)

$\frac { 3m{ v }^{ 2 } }{ 16g }$

(c)

$\frac { \sqrt { 3 } m{ v }^{ 2 } }{ 16g }$

(d)

$​​\frac { 3m{ v }^{ 2 } }{ 8g }$

13. An object moves from positions (6, 8) to (12, 10) in the x-y plane. Magnitude and direction of displacement is

(a)

$\sqrt { 40 }$ and $18.43°$

(b)

$\sqrt { 40 }$ and $71.56°$

(c)

10 and $53°$

(d)

$30°$ and 9

14. A particle moves in xy-plane from positions (2m, 4m) to (6m, srn) is 2 s. Magnitude and direction of average velocity is

(a)

$\sqrt { 2 }$ and ms-1 and $45°$

(b)

2$\sqrt { 2 }$ ms-1 and $45°$

(c)

4$\sqrt { 2 }$ ms-1 and $30°$

(d)

3$\sqrt { 2 }$ms-1 and $60°$

15. A particle, is thrown with a speed u at an angle $\theta$  with the horizontal. When the particle makes an angle $\phi$ with the horizontal, its speed changes to v where

(a)

v= u cos $\theta$

(b)

v= u cos $\theta$ cos $\phi$

(c)

v= u cos $\theta$ sec$\phi$

(d)

v= u sec $\theta$ cos$\phi$

16. The equation of projectile is $Y=\sqrt { 3 } X-\frac { 1 }{ 2 } g{ X }^{ 2 }$ . The velocity of projection i

(a)

1 ms-1

(b)

2  ms-1

(c)

3  ms-1

(d)

1.2  ms-1

17. A person moving horizontally with velocity $\vec{V_m}$ The relative velocity of rain with respect to the person is

(a)

VR + Vm

(b)

$\sqrt{V_R+V_m}$

(c)

VR - Vm

(d)

$\sqrt{V_R^2+V_m^2}$

18. A person moving horizontally with velocity $\vec{V_m}$ Rain falls vertically with velocity $\vec{V_R}$ To save himself from the rain, he should hold an umbrella with vertical at an angle of

(a)

$\tan^{-1}(\frac{V_R}{V_m})$

(b)

$\tan^{-1}(\frac{V_m}{V_R})$

(c)

$\tan\theta=V_m+V_R$

(d)

$\tan^{-1}(V_R+V_m/V_R-V_m)$

19. A car is circulating on a circular path of radius r. At some instant its velocity v and rate of increase of speed is a. The resultant acceleration of the car will be

(a)

$\sqrt { \frac { { v }^{ 2 } }{ { a }^{ 2 } } +{ r }^{ 2 } }$

(b)

$\sqrt { \frac { { v }^{ 2 } }{ r } +a }$

(c)

$\sqrt { \frac { { v }^{ 4 } }{ { r }^{ 2 } } +{ a }^{ 2 } }$

(d)

$\left( \frac { { v }^{ 2 } }{ r } +a \right)$

20. A point starts from rest and moves along a circular path with a constant tangential acceleration. After one rotation, the ratio of its radial acceleration to its tangential acceleration will be equal to

(a)

1

(b)

$2\pi$

(c)

$\frac { 1 }{ 2\pi }$

(d)

$4\pi$

21. Part B

Answer all the Two Mark Questions

10 x 2 = 20
22. What are the steps involved in scientific method?

23. What is Physics?

24. When the sum of two vectors is maximum?

25. Using components methods, add the following vectors.
$\overrightarrow { A } ={ A }_{ x }\hat { i } +{ A }_{ y }\hat { j } +{ A }_{ z }\hat { k }$
$\overrightarrow { B } ={ B }_{ x }\hat { i } +{ B }_{ y }\hat { j } +{ B }_{ z }\hat { k }$

26. What is three dimensional motion? Give example.

27. Write about the properties of components of vectors.

28. Show that if the force acting on the particle is zero, its momentum remains unchanged.

29. Will the momentum remain conserved if some external force acts on the system.

30. A body is acted upon by a number of external forces. Can it remain at rest?

31. Bodies of larger mass need greater initial effort to put them in motion. Why?

32. Part C

Answer all the Three  Mark Questions

10 x 3 = 30
33. How will you measure the diameter of the Moon using parallax method?

34. Write the rules for determining significant figures.

35. Give any three applications of physics in our society.

36. What are fundamental quantities and derived quantities?

37. Write an expression for displacement vector in Cartesian coordinate system and also show graphically.

38. How is a function represented graphically and mathematically.

39. A bullet going with speed 350 m/s enters in a concrete wall and penetrates a distance of 5 cm before coming to rest. Find the deceleration.

40. On a foggy day two drivers spot each other when they are just 80 mts apart. They are travelling at 72 kmh-1 and 60 kmh-1, respectively. Both of them applied brakes retarding their cars at the rate of 5 ms-2. Determine whether they avert collision or not.

41. Using free body diagram, show that it is easy to pull an object than to push it.

42. Explain various types of friction. Suggest a few methods to reduce friction.

43. Part D

Answer all the Five  Mark Questions

6 x 5 = 30
44. Explain the propagation of errors in subtraction, quotient and power of a quantity.

45. Write the rules for "Rounding off" with example

46. A body falling freely descends 0.3m in 0.1s and 0.398m in the next 0.1s in some other planet. Find the value of g in that planet.

47. A van is moving along x-axis. As shown in the figure, it moves from 0 to P in 18s and returns from P to Q in 6s. What are the average velocity and average speed of the van in going from (i) from O to P, (ii) from O to P and back to Q?

48. Describe Galileo's experiments concerning motion of objects on inclined planes?

49. Prove Impulse - Momentum equation.