## Study Questions

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##### PHYSICS (2016) QUIZ STUDY
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.

1.
Myopic defects in the human eye can be corrected through the use of a
.
A. Concave Mirror
B. Concave lens
C. Prism
D. Convex lens

2.
A charged particle is moving in a uniform magnetic field. if the direction of motion of the charged particle is parallel to the magnetic field, the path of the charge will
.
A. Be a straight line
B. Curve inwards
C. Be a parabola
D. Curve outwards

3.
What happens to a water pool on a day when the humidity of the air is very low?
.
A. Temperature decreases
B. Slow evaporation
C. Temperature increases
D. Rapid evaporation

4.
A satellite moves in a circular orbit of radius 4R round the earth. The acceleration of the satellite in terms of g is
.
A. $$\frac{g}{16}$$
B. $$\frac{g}{4}$$
C. $$\frac{4}{g}$$
D. $$\frac{16}{g}$$
Explanation.
$$\frac{g}{R^2}$$ = $$\frac{g}{4^2}$$ = $$\frac{g}{16}$$

5.
I.Chemical II.Sound III.Electricity

Which of the above forms of energy can directly be converted to light energy?
.
A. I and II only
B. II and III only
C. I, II and III
D. I and III only

6.
If the distance between the object and the pinhole of a pinhole camera is reduced by half the size of the image of the object
.
B. Is halved
C. Remains the same
D. Is double

7.
An object is placed 15cm in front of a plane mirror. If the mirror is moved further 5cm away from the object and the image is
.
A. 80cm
B. 40cm
C. 50cm
D. 70cm

8.
Which of the following statements is correct about a machine?
.
A. Efficiency of a machine is always greater than I
B. Efficiency decreases with an increase in friction
C. Velocity ratio depends on friction
D. Mechanical advantage increases with an increase in friction

9.
The instrument used to view stars is the
.
A. Prism binoculars
B. Telescope
C. Film projector
D. Microscope

10.
What is the angular magnification of a telescope having objective and eyepiece lenses of a focal lengths 30cm and 3cm respectively?
.
A. 60
B. 10
C. 30
D. 90
Explanation.
M = $$\frac{y}{x}$$ = $$\frac{30}{3}$$

= 10

11.
A wire of length 10m is cooled from 50oC to 10oC. Calculate the decrease in the length of the wire. [c = 3 x 10-5K-1]
.
A. 1.8 x 10-4m
B. 1.5 x 10-4m
C. 1.5 x 10-3m
D. 1.8 x 10-3m

12.
When an athlete perspires after running, he loses heat through
.
A. Evaporation
B. Conduction
D. Convection

13.
The rate of cooling of a heated quantity of liquid in an enclosure depends on the
.
A. Pressure of the liquid
B. Temperature in the enclosure
C. Pressure of the enclosure
D. Volume of the liquid

14.
The heat required to raise a mass of a substance through 1K is known as
.
A. Specific heat capacity
B. Specific latent heat of vaporization
C. Capacity latent heat of fusion
D. Heat capacity

15.
A boy in a barber's shop sits between two parallel mirrors. The number of images observed by him will be
.
A. Infinite
B. Ten
C. Eight
D. Forty

16.
Semiconductor is a class of solid whose conductivity increases with an increase in
.
A. Pressure
B. Temperature
C. Current
D. Voltage

17.
Which of the following statements is NOT correct?
.
A. Brownian motion is an evidence of the particle nature of matter
B. Atoms combine to form molecules
C. The molecules of matter are in constant motion
D. matter is made up of molecules

18.
A dynamo primarily converts
.
A. Mechanical energy into electrical energy
B. Electrical energy into kinetic energy
C. Potential energy into kinetic energy
D. Kinetic energy into potential energy

19.
A saturated vapour pressure of a liquid increases when the
.
A. Temperature of a liquid increases
B. Volume of the liquid increases
C. Volume of the liquid decreases
D. Temperature of the liquid decreases

20.
What force has to be exerted on a mass 60kg to give it an acceleration of 10ms-2 vertically upwards?
[g = 10ms-2
.
A. 300N
B. 600N
C. 1200N
D. 400N
Explanation.
F = Ma + mg = 60 x 10 x 60 x 10 = 1200N

21.
A metre rule is pivoted at its mid-point with a vertical force of 10N hanging from the distance 30cm from the mid-point. At what distance must a 15N force hang to balance the ruler horizontally?
.
A. 30cm
B. 10cm
C. 20cm
D. 25m
Explanation.
Clockwise moment = Anti-clockwise moment
10 x 30 = 15 x X
X = 20cm

22.
A projectile is fired from the ground level with a velocity of 300ms-1 at an angle of a 30o to the horizontal.
Calculate the time taken to reach the maximum height?
[g = 10ms-2]
.
A. 30s
B. 20s
C. 25s
D. 15s
Explanation.
t = $$\frac{u sin\theta}{g}$$ = $$\frac{300 \text {sin} 30}{10}$$ = 15s

23.
A train with an initial velocity of 20ms-1 is subjected to a uniform deceleration of 2ms-2. The time required to bring the train to a complete halt is
.
A. 40s
B. 10s
C. 20s
D. 5s
Explanation.
t = $$\frac{v - u}{a}$$ = $$\frac{20 - 0}{2}$$

= 10s

24.
Which of the following electromagnetic waves has the shortest wavelength?
.
A. Visible Light
B. Ultraviolet rays
C. Infrared rays
D. Gamma rays

25.
A radioactive isotope has a decay constant of 10-6s-1.
Calculate its half - life?
.
A. 5.93 x 106s
B. 6.93 x 107s
C. 6.93 x 109s
D. 5.93 x 107s
Explanation.
t1/2 = $$\frac{0.693}{\gamma}$$ = $$\frac{0.693}{10^-6}$$

= 6.93 x 107

26.
Which of the following waves is both transverse and mechanical?
.
A. Water waves
C. Sound waves
D. X-rays

27.
Calculate the temperature of 6 moles of an ideal gas at a pressure of 7.6 x 106Nm-2 with a volume of 10-3m3.
[R = 8.3jmol-1K-1]
.
A. 201oC
B. 126oC
C. 153oC
D. 185oC
Explanation.
T = $$\frac{PV}{nR}$$ = $$\frac{7.6 x 10^6 x 10^-3}{6 x 8.3}$$

= 153oC

28.
The relative density of a liquid is the ratio of the
.
A. Mass of water to the mass of an equal volume of liquid
B. Upthrust in the liquid to the upthrust in water
C. Density of water to the density of the liquid
D. Upthrust in water to the upthrust in the liquid

29.
What will happen to the pressure of a gas if its temperature is reduced to -273oC?
.
A. It will decrease
B. it will drop to zero
C. It will increase
D. It will remain constant

30.
Which of the following does Not use magnetic effect of current to function?
.
B. An electric bell
C. A moving coil galvanometer

31.
Vapour is said to be saturated on top of an enclosed liquid if _________
.
A. The rate of condensation is greater than that of vapourization
B. The rate of condensation is equal to that of vapourization
C. There is neither condensation nor vaporization of the liquid
D. The rate of condensation is less that that of vaporization

32.
A pool of water appears to be 1.00m deep when viewed vertically from above. What is the actual depth of the pool?
[Refractive index of water = 1.33]
.
A. 13.300m
B. 0.750m
C. 1.013m
D. 1.330m
Explanation.
n = $$\frac{\text {Read depth}}{\text{Apparent depth}}$$ = 1.33 = $$\frac{Rd}{1}$$

Rd = 1.33 x 1 = 1.330m

33.
Shadows and eclipse result from the
.
A. Reflection of light
B. Rectilinear propagation of light
C. Diffraction of light
D. Refraction of light

34.
Which of the following is obtained when a magenta is mixed with green colour?
.
A. Yellow
B. Blue
C. White
D. Red

35.
Which of the following instruments can be used to measure current in an a.c circuit?
.
A. Hot wire ammeter
B. Moving coil ammeter
C. Tangent galvanometer
D. Moving coil galvanometer

36.
Which of the following statements about wave motion is correct?
.
A. Electromagnetic waves are transverse
B. Transverse waves do not require a medium for propagation
C. Longitudinal waves vibrate perpendicular to the direction of travel
D. All mechanical waves are longitudinal

37.
A satellite revolving around the earth is kept on its orbit by
.
A. Centripetal forces only
B. Centripetal and frictional forces
C. Centrifugal forces only
D. Centripetal and centrifugal forces

38.
A manometer is an instrument used for measuring
.
A. Relative density of liquid
B. Pressure in liquids and gases
C. Humidity
D. Atmospheric pressure

39.
A body which weighs 50N in air displaces 3.7kg of water when partially immersed in water. Calculate the upthrust on the body?
.
A. 8.7N
B. 37.0N
C. 87.0N
D. 13.0N
Explanation.
Upthrust = Weight or water displaced
= 3.7 x 10 = 37N

40.

The impulse of a force is deduced from Newton's second law as

.
A.

F = ma

B.

F = m( $$\frac{v - u}{t}$$)

C.

F = mg

D.

F = mv - mu

41.
Boiling occurs when the vapour pressure of a liquid is
.
A. At the evaporation point
B. Less than the atmospheric pressure
C. Greater than the atmospheric pressure
D. Equal to the atmospheric pressure

42.

If the magnification of a virtual image formed by an object 10cm from a convex less is 3, then the focal length of the lens is

.
A.

10cm

B.

20cm

C.

25cm

D.

15cm

Explanation.

M = $$\frac{v}{u}$$ = 3 = $$\frac{v}{30}$$. V = 30m

$$\frac{1}{u}$$ + $$\frac{1}{v}$$ = $$\frac{1}{f}$$ = $$\frac{1}{10}$$ - $$\frac{1}{30}$$ = $$\frac{1}{f}$$

$$\frac{3 - 1}{30}$$ = $$\frac{1}{f}$$

f = $$\frac{30}{2}$$ = 15cm

43.
An electron in a hydrogen atom makes a transition from the ground level to the third level. If the energy at the ground level,calculate the energy at the third level.
[h = 6.6 x 10-34Js; f = 1015Hz]
.
A. 1.41eV
B. 1.71eV
C. 1.61eV
D. 1.51eV
Explanation.
E = $$\frac{E_o}{n^2}$$ = $$\frac{13.6}{3^2}$$ = $$\frac{13.6eV}{9}$$

= 1.51eV

44.

In the diagram above, which of the following velocity-time graphs shows uniform acceleration of a body from rest?

.
A.

C

B.

D

C.

B

D.

A

45.

In the diagram above, the neutral point is at

.
A.

R

B.

X

C.

S

D.

P

46.

From the diagram above, the measuring accuracy of the micrometer screw gauge is

.
A.

4.78mm

B.

4.16mm

C.

4.66mm

D.

4.70mm

47.

In the diagram above, the direction of the force between N and S in the magnetic field is

.
A.

MP

B.

SN

C.

NS

D.

PM

48.
Which of the following statements is Not true about atoms?
.
A. Atom of different elements have different atomic weights
B. The mass of an atom is concentrated in the nucleus
C. An atom is made up of a nucleus and number of electrons
D. Atoms of all elements are identical

49.
The frequency of beats produced when two tunning forks of frequencies 258Hz and 270Hz are sounded close to each other
.
A. 6Hz
B. 264Hz
C. 528Hz
D. 12Hz
Explanation.
Beat = f2 - f1 = 270 - 258 = 12Hz

50.
Calculate the inductance of a coil of resistance 30$$\Omega$$ connected to a 100V a.c source if the coil draws an r.m.s current of 2A
.
A. 0.60H
B. 2.50H
C. 1.25H
D. 0.04H