Monday, 18 March 2019

NDA PAST QUESTIONS ON PHYSICS 2014

1. When a ball of mass 2kg moving with a velocity of 10 ms-1 collides head-on with a ball of mass 3 kg, and both moves together after the collision, the common velocity is ___.
A. 5 ms-1 and energy is lost
B. 4 ms-1 and energy is lost
C. 2 ms-1 and energy is gained
D. 6 ms-1 and momentum is gained




2. If r is the radius of the earth and g is the acceleration at its surface, then the acceleration g at an orbit distance R from the centre of the earth is given by
A. gI/g =r/R
B.  gI/g =r2/R2
C. gI/g =R2/r2
D. gI/g =(R-r)2/r2


3. When water is a bucket is whirled fast overhead the water does not fall out at the top of the motion because
A. the centripetal force on the water is greater than the weight of water
B. the force on the water is opposite to gravity
C. the reaction of the bucket on the water is zero
D. the centripetal force on the water less than the weight of water

4. An object of mass 4kg moves round a circle of radius 6 m with a constant speed of 12 ms-1. calculate the angular velocity.
A. 2 rads-1
B. 4 rads-1
C. 6 rads-1
D. 8 rads-1

5. A flat plate is cut in the shape of a square of side 20.0 cm with an equilateral triangle of side 20.0 cm adjacent to the square. Calculate the distance of the centre of mass from the apex of the triangle.
A. 22.6 cm
B. 20.6 cm
C. 21.6 cm
D. 22.0 cm

6. A mercury-in-glass thermometer reads 20° at the ice point and 1000 at the steam point. Calculate the Celsius temperature corresponding to 70° on the thermometer.
A. 41.0°c
B. 50.0°c
C. 62.5°c
D. 70.0°c

7. A brass rod is 2m long at a certain temperature. Calculate the linear expansion of the rod for a temperature change of 100k. (Take the linear expansivity of brass as 1.8 x 10-5 K-1
A. 0.3600 m
B. 0.1800 m
C. 0.0360 m
D. 0.0036 m

 8. A force of 100 N is needed to lift a load of 50 N using a pulley system whose velocity ratio is 4. The efficiency of the system is __.
A. 0.5%
B. 8%
C. 12.5%
D. 50%

 9. A small boy is standing in the corridor of a train that is travelling at 100km/h, he jumps up to the height of about 0.3m when he lands his feet should touch the floor.
A. long way ahead of where he was standing
B. a short way ahead of where he was standing
C. exactly where he was standing
D. a short way behind where he was standing

10. A piece of rubber 10 cm long stretches 6 mm when a load of 100 N is hung from it. What is the strain?
A. 60
B. 6
C. 6 x10-3 
D. 6 x 10-2 

11. The following are derived units except __.
A. M
B. Kg/m
C. N
D. Kg

12. Which of the following statements is true of the vector shown below?
A. Z is the equilibrium of x and y
B. Z is the resultant of x and y
C. X is the resultant of z and y
D. Y is the resultant of x and y

13. A man walks 10km due south. The displacement of the man from the initial position is __.
A. 10km South
B. 27.6km 300N of East
C. 20km North
D. 22.36km 63.4 South of East

14. An object starts from rest and moves with a uniform acceleration. Which of these quantities varies/vary directly with time?
I. Velocity
II. Displacement
III. Acceleration

A. I only
B. II only
C. III only
D. I and III

15. A stone is thrown horizontally from the top of a tall building with a velocity of 10 m/s. If the stone falls at a distance of 50 m from the foot of the building, calculate the height of the building
A. 75 m
B. 100 m
C. 125 m
D. 150 m

16. A vehicle of mass m is driven by an engine of power P from rest. Find the minimum time it will take to acquire a speed v.


17. A box of mass 40kg is being dragged along the floor by a rope inclined at 600 to the horizontal; The frictional force between the box and the floor is 100N and tension of the rope is 300 N, How much work is done in dragging the box the through a distance of 4 m?


A. 680 J
B. 400 J
C. 200 J
D. 100 J

18. Which of the following statement are true about frictional force?
I. It is always a disadvantage
II. It is sometimes a disadvantage
III. It always exists where there is a relative motion of two bodies that are in contact
IV. It is sometimes very useful
A. I and III only
B. I and IV only
C. II and III only
D. II and IV only

19. The energy contained in a wire when it is extended by 0.02 m by a force of 500 N is  __.
A. 5 J
B. 10 J
C. 10J
D. 10J

20. A copper cube weighs 0.25 N in air, 0.17 N when completely immersed in paraffin oil and 0.15 N when completely immersed in water. The ratio of up thrust in oil to upthrust in water is
A. 3: 5
B. 4: 5
C. 7: 10
D. 13: 10

21. A wheel and axle is used to raise a load of 500 N by the application of an effort of 250 N. If the radii of the wheel and the axle arc 0.4 cm and 0.1 cm respectively, the efficiency of the machine is
A. 20%
B. 40%
C. 50%
D. 60%

22. Which of the following phenomenon can occur only with sound waves?
A. interference only
B. interference and distraction
C. interference, diffraction and refraction
D. diffraction and refraction

23. A whistle is blown and an echo is heard from a distant cliff three seconds later. If the speed of sound in air is 0.33 kms-1, how far away is the cliff?
A. 0.05 km
B. 0.1 km
C. 0.5 km
D. 1 km

24. If radio waves travel at a speed of 3 x 105 kms-1; then the wavelength of a radio wave of frequency 1.5 MHz is ___.
A. 200 m
B. 5.0 m
C. 0.20 m
D. 450 m

25. Find the wavelength for a radio station broadcast at a frequency of 200 KHz. if the speed of the wave is 3 x 108 m/s.
A. 0.50 x 10-3 m
B. 0.50 x 10-5 m
C. 1.5 x 103 m
D. 1.5 x 10-3 m

26. An opaque object is floating 3.5 cm above the bottom of a liquid but appears to be floating 5.0 cm helms the surface. If the liquid is 10.0 cm deep. Its refractive index is  __.
 A. 0.20
 B. 0.78
 C 1.19
 D 1.30

27. Which of the following statements about lenses is true?
A. a diverging lens may produce a real or virtual image
B. a diverging lens always produce an inverted image
C. a diverging lens cannot produce a magnified image
D. a converging lend cannot produce a diminished image

28. An eclipse of the moon occurs when the earth lies in a direct line between the sun and the moon, such an eclipse does not occur every month, however. became
A. the moon will be rotating about its own axis at that time.
B. the earth will be rotating about its own axis at that time
C. the revolution of the moon about the earth is in a different plane to the revolution of the earth about the sun
D. the earth takes than one month to revolve around the sun





29. An object is illuminated by an extended source. The umbra consists of the region between

A. 3 and 4
B. 1 and 6
C. 2 and 5
D. 1 and 2

30. Snell's Law concerning the passage of light from one medium to another state that

A. the size of the angle of incidence equals the size of the angle of refraction
B. the angle of incidence equals the angle of refraction
C. the ratio of the angle of refraction is constant
D. the ratio of the angle of incidence to the angle of refraction is constant



31. In the periscope shown above, the image will appear at the point

A. t
B. p
C. r
D. s

32. Thermal equilibrium between two objects exist when

A. the temperatures of both objects are equal
B. the quantity of heat in both objects is the same
C. the heat capacities of both objects are the same
D. one object loses heat continuously to the other

33. An open pipe closed at one end produces its first fundamental note. If the velocity of sound in air is v and L the length of the pipe, the frequency of the note is



34. Given that Young's modulus for aluminium is 7.0 x 1010Nm-2 and density is 2.7 x 10 kgm-3
Find the speed of the sound produced if a solid bar is struck at one end with a hammer.
A. 5.1 x ms-1
B.  4.2  x 103ms-1
C. 3.6 x 103ms-1
D. 2.8 x 103ms-1

35. A 2000 W electric heater is used to heat a metal object of 5kg initially at 10°C. If a temperature rise of 30°C is obtained after l0 min, the heat capacity of the material is
A. 6.0 x 10J°C-1
B. 4.0 x 10J°C-1
C. 1.2 x 10J°C-1
D. 8.0 x 10J°C-1

36. An electron of charge 1.6 x 10-19 C is accelerated between two metal plates. If the kinetic energy of the electron is 4.4 x 10-17J, the potential difference between the plates is
A. 30 V
B. 40 V
C. 275 V
D. 400 V

37. A magnetic field is said to exist at a point if a force is  __.
A. exerted on a stationary charge at a point
B. exerted on a moving charge at a point
C. deflected at the point
D. strengthened at the point

38. Which of these statements is true of a soft-iron?
I. It retains its magnetism much longer than steel It is more easily magnetized than steel
IT is more easily demagnetized than steel
IV. It produces a stronger magnet than steel.
A. I and II
B. I, II and IV
C. II and III
D. I, II, III and IV

39. Which of the following pairs of light rays shows the wildest separation in the spectrum of white light?
A. Blue and Red
B. Green and Yellow
C. Indigo and Violet
D. Orange and Red

40. The most suitable cell used for short interval switches in electric bells is a  __.
A. lead-acid accumulator
B.  Daniel cell
C. Lachance cell
D. Nickle iron accumulator

ANSWERS
1. B
2. C
3. D
4. A
5. A
6. B
7. D
8. C
9. C
10. D
11. D
12. C
13. A
14. A
15. C
16. A
17. C
18. C
19. A
20. B
21. C
22. C
23. C
24. A
25. C
26. D
27. C
28. A
29. A
30. C
31. C
32. D
33. A
34. A
35. C
36. C
37. C
38. D
39. A
40. A