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# WAEC Physics Questions and Answers for 2021/2022

Welcome to 2021 WAEC Physics questions and Answers. You will find WAEC Physics Objective Answers, WAEC Physics Essay 2021, WAEC 2021 Physics and the tips you need to pass your waec Physics examination at ease.

## WAEC Physics Objectives And Essay Answers 2021

1-10: AAABACCDDB
11-20: ACCDCBCBAC
21-30: CCCBBDDBBB

(6)
(i) Reflection
(ii) Refraction
(iii) Diffraction

No 7a

The scientific principle underlying the operation of a fibre optics is the principle of total internal reflection by which light signals can be transmitted from one place to another with a negligible loss of energy.

(7bi)
Core: The core is the light transmission area of the fibre, either glass or plastic cladding. The function of the cladding is to provide a lower refractive index at the core interface in order to cause reflection within the core so as to enable light waves transmitted through the fibre.

(7bii)
Cladding: It functions as a gadget that provides a clear refractive index at the core interface in order to cause reflection within the core so that light waves are transmitted through the fibre.

The questions provided below are WAEC Physics questions and answers.

Scroll to the bottom for today’s Physics answers.

1. The instrument that measures the relative density of light is
A. thermometer
B. hydrometer
C. spring balance
D. beaker

2. What is the speed of a body vibrating at 50 cyclic per second

3. The action of blotting paper on ink is due to
A. diffusion
B. osmosis
C. capillarity
D. surface tension

4. When two mirrors are placed at an angle of 900 to each other, how many images will be formed when an object is placed in front of the mirrors
A. 5
B. 4
C. 3
D. 2

5. If silicon is doped with phosphorus, what type of semiconductor material will be formed?
A. Zener material
B. P-n junction
C. n-type
D. p-type

6. A car of mass 800kg attains a speed of 25m/s in 20 secs. The power developed in the engine is
A. 1 . 25 x 104 W
B. 2 . 50 x 104 W
C. 1 . 25 x 106W
D. 2 . 50 x 106 W

7. When the brakes in a car are applied, the frictional force force on the tyres is
A. is a disadvantage because it is in the direction of the motion of the car
B. is a disadvantage because it is in the opposite direction of the motion of the car
C. is an advantage because it is in the direction of the motion of the car
D. is an advantage because it is in the opposite direction of the motion of the car

8. If the stress on a wire is 107NM–2 and the wire is stretched from its original length of 10.00 cm to 10.05 cm. The young’s modulus of the wire is
A. 5. 0 x 104 Nm-2
B. 5. 0 x 105 Nm-2
C. 2. 0 x 108 Nm-2
D. 2. 0 x 109 Nm-2

9. A solid weigh 10.00 N in air, 6 N when fully immersed in water and 7. 0 N when fully immersed in a liquid X. Calculate the relative density of the liquid, X.
A. 5/3
B. 4/3
C. 3/4
D. 7/10

See: WAEC Chemistry Questions and Answers

10. When temperature of a liquid increases, its surface tension
A. Decreases
B. Increases
C. Remain Constant
D. Increases then decreases

11. A gas at a volume of V0 in a container at pressure P0 is compressed to one-fifth of its volume. What will be its pressure if the magnitude of its original temperature T is constant?
A. P0/5
B. 4P0/5
C. P0
D. 5P0

12. A piece of substance of specific head capacity 450JKg-1K-1 falls through a vertical distance of 20m from rest. Calculate the rise in temperature of the substance on hitting the ground when all its energies are converted into heat. [g = 10ms-2]
A. 2/9°C
B. 4/9°C
C. 9/4°C
D. 9/2°C

13. I. A liquid boils when its saturated vapour pressure is equal to the external pressure
II. Dissolved substances in pure water lead to increase in the boiling point.
III. When the external pressure is increased, the boiling point increases.
IV. Dissolved substances in pure water decrease the boiling point.

14. Which combination of the above are peculiarities of the boiling point of a liquid?
A. I, II and III
B. I, II, III and IV
C. I, II and IV
D. II, III and IV

15. The temperature gradient across a copper rod of thickness 0.02m, maintained at two temperature junctions of 20°C and 80°C respectively is
A. 3.0 x 102Km-1
B. 3.0 x 103Km-1
C. 5.0 x 103Km-1
D. 3.0 x 104Km-1

16. Calculate the mass of ice that would melt when 2kg of copper is quickly transferred from boiling water to a block of ice without heat loss;
Specific heat capacity of copper = 400JKg-1K-1
Latent heat of fusion of ice = 3.3 x 105JKg-1
A. 8/33kg
B. 33/80kg
C. 80/33kg
D. 33/8kg

17. A semiconductor diode is used in rectifying alternating current into direct current mainly because it
A. allows current to flow in either direction
B. is non-linear
C. offers a high input resistance
D. allows current to flow only in one direction

18. if ∆x is the uncertainty in the measurement of the position of a particle along the x-axis and ∆Px is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is given as
A. ∆x ∆Px ≥ h
B. ∆x ∆Px = 0
C. ∆x ∆Px < h
D. ∆x ∆Px = ∞

19. When a ship sails from salt water into fresh water, the fraction of its volume above the water surface will
A. increase
B. decrease
C. remain the same
D. increase then decrease

20. I. Its velocity is constant
II. No work is done on the body
III. It has constant acceleration directed away from the centre
IV. The centripetal force is directed towards the centre

1)
Velocity of projection U_p =10m/s
T= sqr root 2h/g Where H=1
G=10
T=sqr root 2*1/10
=sqr root 0.2
=0.447s
V=UsinTita + gt V=10sin90 + 10*0.447
V=10 +4.45
V=14.5m/s
=================

(2)
(i) The position of the ion of the atm of the element in the
electrochemical(activity)series.
(ii) the nature of the electrode.
(iii) the concentration of the electrolyte
====================================
3)
l=6.5m
d=3.0mm=0.003m
e=0.20mm=0.0002m
F=60N
stress=F/A
A=pie*D^2/4
=3.142*0.003^2/4
=3.142*9*10^-6/4
=7.065*10^-6/4m^2
stress=60/7.065*10^-6
=8.49*N/m^2

(7)
Doping of semiconductor increases the number of holes and electrons in
the semiconductor, thereby making it impure which makes it to be useful
or active.

## WAEC Physics Essay and Objective 2021 (EXPO)

The above questions are not exactly 2021 WAEC Physics questions and answers but likely WAEC Physics repeated questions and answers.

These questions are for practice. The 2021 WAEC Physics expo will be posted here soon.

1 DACAACBBCC

11 BDBABBACAC

21 BCBACBBACA

31 BDDDDACCCA
41 AAAABBCBBC

completed

No (2a)
Flat metal plate are mainly used to collect heat for space heating in solar panels for heat transfer.

(2b)
Thermal insulator is used for reduction of heat transfer between objects in thermal contact

(2c)
tubes is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.

(3a)
highly purified silica glass.

(3b)
To confine the optical signal in the core the refractive index of the core must be greater than that of the cladding.

No (7)
(i)Coherence
(ii)Directionality
(iii)Monochromatic

No (1)
Original length Lo= 3m
Extension e = 310 = 3*3= 9m
F×e
F=ke where k = 982.3NM-²
F=982.3*9=8,840.7N
The five that produce the extension F = 8.840.7N

No (5)
Escape velocity = VE
Radius of the earth = R
Acceleration due to gravity = 10ms²
Escape velocity Be=√2R
VE=√2*10R
VE=√20R

No (6)
Angle at horizontal θ = 30°
Time of light , T = 25sec
Velocity of projection u = ?
But T=2using sinθ/g
25= 2u*sin30/10
25=0.5u/5
0.5u=125
U=125/0.5
=250ms-¹

(8ai)
A torque is defined as a measure of the force that can cause an object to rotate about an axis

(8aii)
Factors that determine torque are;
– The magnitude of the force
– The angle between the force and the lever arm

(8bi)
Free fall simply means the act of which are objects fall freely under the influence of gravitational force. An object under free fall does not encounter air resistance

(8bii)
Height of tower H = 40.0m
Velocity v = 10.0m/s, time t= ? , g=10.0m/s

Using the relation
S= ut + 1/2gt^2
H= ut + 1/2gt^2
40= 10t + 1/2*10t^2
4= t + t^2/2
= t^2 + 2t – 8=0 ( solving quadratically)
= (t+4)(t-2)=0
t+4=0 or t-2=0
t= -4 or t=2

Therefore time to fall on the ground t=2s

(8c)
(8c)
R.d of oil =R1 = 0.72
R.d of water = R2=1.00
R.d of liquid= R1/R2= 0.72/1 = 0.72
R.d = density of wood(P1)/density of water(P2)
0.72=P1/1.00
P1= 0.72*1.00=0.72g/cm³
But density of wood= mass of wood/volume of wood
0.72= mass of wood/8*8*8
Mass of wood = 0.72*512 = 368.64g

Use this one

(10ai)
Critical angle: this is the angle of incidence that
provides an angle of refraction of 90-degrees.

(10aii)
(i) Light must travel from a denser medium to a rarer medium and
(ii) the angle of incidence inside the denser medium must be greater than the critical angle.

(10aiii)
-In elescopes application
-In microscopes applications
-In the binoculars

(10b)
(i)Bending of light;If light is moving from rarer to denser medium then it moves towards the normal.
If it is moving from denser to rarer medium then it moves away from the normal.

(ii)Change in wavelength of light

(10ci)
(i)myopia
(ii)Long sightedness
(ii)short sightedness

(10cii)
(i)concave lens
(ii)Convex lens
(iii)Contact lenses

(10di)
convex mirror has a wider field of view

(10dii)
The disadvantages of convex mirror are that they make it appear like those objects are at a more noteworthy distance than they actually are.

(4)
V∝ Tx μy
LT-∝(MLT-²)x(MLT-¹)y
LT-¹∝ m*L*T-²x x m y L-y
LT-¹∝ m(x+y)L(x-y)T-²x
Comparing
X-y=1
X+y=0
-2x=1
From equation 3
X=½
Putting x = ½ into (eq) 2
y=-½
Equation is
V∝ T½ μ-½
V∝ √T/μ
V= k√T/μ
Where k is constant

### Tips to Pass WAEC 2021 Physics Questions

#### 1. Be Positive in Your Thought

It is obvious that until your mindset is positive, your life will not be positive. As you prepare for WAEC 2021, you must develop a positive mindset towards your fate. Don’t say, “WAEC Physics is very hard I don’t know whether I will pass” and don’t believe anyone that says you cannot pass WAEC 2021 Physics on your own.

Have the mentality, “If others passed WAEC 2021 Physics in the past, then I will be like them. Refuse to be identified with failure or those that failed in the past.

Even if this year’s WAEC Exam is not your first time, it doesn’t mean that you cannot pass WAEC 2021 Physics this time around. Sit for maths 2021/2022 with a refined mindset. Nothing will make you fail WAEC 2021. Until your mindset is positive, your life will not be positive.

#### 2. Be Mindful of the Friends You Keep

If you are really serious about passing WAEC 2021 Physics, try and avoid bad companies. They will discourage and engage you in activities that will not enhance your success. Remember that their mindset may not correspond to yours.

#### 3. Target High

If you have made up your mind to pass WAEC 2021, the next thing you should do is set targets. Write down the type of grades you want in WAEC 2021. If you want all As, zero Fs and Zero Es then you should start planning it now.

Make sure you create a timetable and master plan to achieve your set goals. Remember, it takes nothing to dream but it takes everything to focus on your dream.

#### 4. Study Using the Recommended WAEC Physics Textbooks

One of your plans should be to get the WAEC 2021 Physics recommended textbooks. Normally, the West African Examination Council recommends books for the examination.

But apart from WAEC 2021 Literature in English where certain novels are compulsory, you are free to use any good textbook to prepare for WAEC 2021 Physics exam. Some topics are more difficult to understand.

If you have any topic you are finding difficult to understand, then get another textbook that will make things simple for you.

#### 5. Study WAEC Physics Past Questions:

This is a very good plan. Since WAEC 2020 and WAEC 2021 are of the same standard, you could use the same past questions to study for both. If you are confused about how to get neco or waec past questions. They are sold in good bookshops around.

It is possible that the school where you registered could offer to give you some current past questions that will help you in WAEC 2021 Physics.

#### 6. Start Preparing for WAEC 2021 :

Stop wasting your time. Now that you have gotten textbooks and past questions, the next thing is to begin your reading. Early reading and practice is good for you; you will pass well on WAEC 2021 Physics

#### 7. Solve and try to understand every example and exercise you see in textbooks

It is very unfortunate that Secondary school students are fond of skipping exercises and even examples while studying textbooks.

They loved notebooks so much that they could ask, “can I read my Physics notebook and pass WAEC 2021?”. Don’t be scared of attempting exercises; they are there to help you. Face it and overcome it!

#### 8. Test yourself after a study by reading WAEC physics past question

This is a good practice. Once in awhile, answer full one year Physics past questions on your own without checking the answers. Then mark to see your score. This will help you in many aspects.

#### 9. Practise Regularly

Don’t get discouraged when certain topics are annoying, keep on practicing until you master everything. Never give up and never say never. Keep on keeping on….

#### 10. Create Break Time

Create time for yourself where you play and ease off stresses. Do not overwork yourself; it can make you waste time unnecessarily. One you work more than necessary, you are not gaining anything.

#### 11. Revise your Previous studies

Doing constant practice is a good idea for WAEC 2021. Don’t just read a topic and forget about it. Revision helps; always go through what you have read over and over again.

#### 12. You can Attend WAEC Preparatory Classes

Attending regular classes makes it easier for you to do well in WAEC 2021 Physics. Do not feel too big to learn from teachers no matter how small or dull they may be. You can also attend other classes that may help outside your normal classes.