Question – 1
1. What would be the work done by a force to stop a car of mass 500 kg moving with a velocity of 24 m/s?

A. 144000 J

B. 100000 J

C. 12000 J

D. 6000 J
 E. 169000 J
 Answer:A
 Answer Explanation:W = KE_{2} – KE_{1} Or W = 1/2 m(v^{2} – u^{2})
W = 1/2 X 500 X (0^{2} – 24^{2})
Or W = 144000 J
Negative sign is because work is done in stopping the car (retardation). Same would be coming in positive if the work is done in moving the car. Hence, A is the correct answer option.
Question – 2
2. A car starts from a point A at 9 AM and reaches point B at 11 AM. If A and B are separated by 100 km and the car is moving with uniform speed, what is the speed of the car for the entire travel in m/s?

A. 15.7 m/s

B. 13.9 m/s

C. 11.3 m/s

D. 10.4 m/s
 E. 14.5 m/s
 Answer:B
 Answer Explanation:Speed is given as v = d/t
v = 100/2 or v = 50 km/h
Convert hours into seconds and km into m.
50 km/h = 50 X 1000/3600 m/s
or 50 km/h = 13.9 m/s
Hence, B is the correct answer option.
Question – 3
3. A rotor with uniform angular speed of 210 s1 needs a torque of 250 Nm from an engine. What would be the power of the engine required for the torque?

A. 54500 W

B. 52500 W

C. 34600 W

D. 1.19 W
 E. None of the above choices
 Answer:B
 Answer Explanation:Power associated with torque is given as P = ?? ??
P = 250 X 210
Or P = 52500 W
Hence, B is the correct answer option.
Question – 4
4. What would be the number of electric lines of forces coming out of a unit charge?

A. 5.5 X 10^{7}

B. 8.5 X 10^{7}

C. 2.15 X 10^{7}

D. 1.11 X 10^{5}
 E. 1.81 X 10^{8}
 Answer:E
 Answer Explanation:Electric lines of forces are nothing but electric flux lines. Electric flux originating from a charge is given as
?? = Q/??_{0}——(1)
?? = (1.6 X 10^{19}) / (8.85 X 10^{12}) Or ?? = – 1.81 X 10^{8}
Negative sign signifies that the electric field lines for an electron are inwards rather than outwards. Neglecting the negative sign, number of electric lines of force becomes 1.81 X 10^{8}. The result suggests that, electric flux for an electron is of a very minute quantity.
Hence, E is the correct answer option.
Question – 5
5. A tuning fork vibrates with a frequency of 500 Hz. If the speed of sound in air is 343 m/s, what is the distance the sound travels when the tuning fork makes 100 oscillations?

A. 34.3 m

B. 50.4 m

C. 5 m

D. 76.8 m
 E. 68.6 m
 Answer:E
 Answer Explanation:
v = ????
343 = 500 X ?? Or ?? = 0.686 m
This is the distance which the sound travels in one oscillation. The distance traveled in 100 oscillations is d = 100 X 0.686 m Or d = 68.6 m
Hence, E is the correct answer option.
Question – 6
6. A force acting on a body of mass 10 kg changes its velocity from 3 m/s to 6.7 m/s in 20 seconds. What is the magnitude of the force applied on the body?

A. 10 N

B. 3.77 N

C. 1.85 N

D. 4.55 N
 E. 2.33 N
 Answer:C
 Answer Explanation:F = m(vu)/t
F= 10 X (6.73)/20
Or F = 1.85 N
Hence, C is the correct answer option.
Question – 7
7. Which of the following is a unit of power?

A. J

B. Nm/s

C. W/s

D. W/s
 E. None of the above choices
 Answer:B
 Answer Explanation:
P = W/t and W = F.d
SI unit of force (F) is N, displacement (d) is m and time (t) is s.
Therefore P = Nm/s Or, P = Nm/s
Hence, B is the correct answer option.
Question – 8
Which of the following statement(s) is true in accordance to the given figure?

A. 2

B. 1

C. 3

D. Both 1 and 2
 E. Both 2 and 3
 Answer:A
 Answer Explanation:Force experienced by the beta particle is given as F = qvB sin ??
F = 1.6 X 10^{19} X 10^{4} X 0.01 X sin 90^{o}
F = 1.6 X 10^{17} X 1 N
F = 1.6 X 10^{17} N
Hence, B is the correct answer option.
Question – 9
9. What is the buoyant force exerted on a 20 cm^{3} block of iron submerged completely inside water?

A. 0.234 N

B. 0.111 N

C. 2.289 N

D. 1.34 N
 E. 0.196 N
 Answer:E
 Answer Explanation:Buoyant force is given as F_{B} = ??gV
As the block is submerged completely, volume of water displaced is equal to the volume of the block = 20 cm^{3}.As the volume is given in cm^{3} we need to convert it into m^{3}.
F_{B} = 1000 X 9.8 X 2 X 10^{5}
Or F_{B} = 0.196 N
Hence, E is the correct answer option.
Question – 10
10. A particle in SHM has a time period of 3 s and amplitude of 0.1 m. What is the displacement of the particle after 1 s?

A. 0.011 m

B. 0.23 m

C. 0.087 m

D. 0.754 m
 E. Zero
 Answer:C
 Answer Explanation:
y(t) = Asin(2??/T)t
y(1) = 0.1 X sin(2??/3)1
y(1) = 0.1 X ???3/2 Or y(1) = 0.087 m
Hence, C is the correct answer option.
Question – 11
11. Which of the following consist of the highest energy photons?

A. Xray

B. Visible light

C. Infrared

D. Radio waves
 E. Microwaves
 Answer:A
 Answer Explanation:All of the options given above are electromagnetic waves. They travel at 3 X 10^{8} m/s. Radio waves have energy in order of 10^{9} eV (electronvolt) to 10^{6} eV. Microwaves have energy in order of 10^{5} eV to 10^{2} eV. Infrared have energy in order of 1 to 10^{2} eV. Visible light have energy in order of 1.6 eV to 3.2 eV. Xrays have energy in order of 10^{2} to 10^{5} eV. Hence on comparing energies of all the electromagnetic waves given above, Xray has the highest energy. Hence, A is the correct answer option.
Question – 12
12. Consider the figure given below for a system of two iron blocks connected with a common pulley. If the block A weighs 200 N, what would be the mass of the iron block B to keep the whole system in static equilibrium?

A. 20.41 kg

B. 15.57 kg

C. 22.23 kg

D. 34.45 kg
 E. 21.45 kg
 Answer:A
 Answer Explanation:As the whole system is in static equilibrium, there will be no motion in the blocks. In other words, weight of both the iron blocks should be the same.
W = mg
200 = m X 9.8
Or m = 20.41 kg
Therefore, A is the correct answer option.
Question – 13
13. Air is filled in a piston of capacity 100 liters at 313 K. At what temperature should the piston be heated so that volume increases to 120 liters for an isobaric process?

A. 375.6 K

B. 373 K

C. 300.45 K

D. 413.5 K
 E. 343.7 K
 Answer:A
 Answer Explanation:Isobaric process is carried out at a constant pressure. Since, pressure is constant here, we have to apply Charles’s law. According to Charles’ law
V_{1} / T_{1} = V_{2} / T_{2}
100/313 = 120/T_{2} Or T_{2} = 375.6 K
Hence, A is the correct answer option.
Question – 14
14. A spring balance measures the weight of a block of ice as 400 N. What is the mass of the block of ice?

A. 34.65 kg

B. 45.66 kg

C. 40.82 kg

D. 24.87 kg
 E. 76.56 kg
 Answer:C
 Answer Explanation:
W = mg
400 = m X 9.8
Or m = 40.82 kg
Hence, C is the correct answer option.
Question – 15
15. What would be the power of a convex lens of focal length 10 cm?

A. 0.2 dioptre

B. 0.1 dioptre

C. 10 dioptre

D. 10 dioptre
 E. 0.05 dioptre
 Answer:C
 Answer Explanation:Power of a lens is given as P = 1/??
Power of converging or convex lens is positive. Therefore P = 1/10 cm
SI unit of power is m1. Hence we need to convert the unit from cm^{1} to m^{1}.
P = 1/0.1 Or P = 10 m^{1}
There is another SI unit for power which is equivalent to m^{1}and is known as dioptre.
Therefore P = 10 dioptre. Hence, C is the correct answer option.