January 16, 2022 WAEC Physics Essay & OBJ Questions and Answers for 15th September 2021

WAEC Physics Essay & OBJ Online Questions and Answers for 15th September 2021

Are you searching for Physics – Essay & OBJ Answers for 15th September 2021? Then you are at the right place.

Our WAEC Physics – Essay & OBJ Answers and Expo for 15th September 2021 is absolutely free and will be updated 1:30 mins before the start of the examination.

WAEC Physics – Essay & OBJ Answers and Online Expo for 15th September 2021

WAEC Physics – Essay & OBJ Answers for 15th September 2021

Time: 8:30am – 11:30am

Physics – Essay & OBJ Answers for 15th September 2021

–  WAEC Physics – Essay & OBJ Answers for 15th September 2021 Section A Answers…..

–  WAEC Physics – Essay & OBJ Answers for 15th September 2021 Section B Answers….

The waec Physics answers 2021 questions for essay and objective exam paper can now be seen here. The West African Examination Council (WAEC) Physics for SSCE will be written on 15th September 2021.

The Waec Physics (Essay) paper will start at 9:30 am and will last for 2hrs while the Physics (Objective) exam will commence at 11:30 am and will last for 1hr.

WAEC Physics Essay & OBJ Online Questions and Answers for 15th September 2021

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

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 107NM2 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

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

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(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.

WAEC Physics Essay & OBJ Online Questions and Answers for 15th September 2021

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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.

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(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

Things you need to know about WAEC Physics examination

First, you should note that you have 2 hours thirty minutes to write your WAEC Physics examination. Your Objective part (section A) contains 60 questions which you are expected to answer all while the theory part contains 5 questions which you are expected to answer any three questions of your choice. All questions carry equal mark.

How to pass senior WAEC Physics examination

Have a strong desire to succeed

The WAEC Physics 2021 exam is primarily for individuals who are determined to pass with a high score.

Any applicant who has not made up his or her mind to pass the upcoming Physics exam with an outstanding grade is not ready to pass.

So, stay cheerful and study your books, rather than following your slacker buddies who believe in miracles on exam day.

2. Have self-assurance

Another component that influences a candidate’s performance is self-confidence. Promise yourself that you will do everything by yourself, and everything will be extremely simple for you.

Because of a lack of self-confidence, many pupils cancel the correct answers in order to replicate the incorrect ones. You are the miracle of the day if you study and pray diligently.

Manage your time in the examination hall wisely

It is risky to remain in one question for more than the expected time. For objectives, you should be able to answer all your questions 15 minutes before the exam ends. Use the remaining time to dot your ‘I’s and cross your ‘T’s. In other words, use it to go through your work and make the necessary corrections.

For the essay part of the exam, ensure you do not exceed he proper time for each question. No matter how simple or hard a question would be, don’t dwell much on it.

To be able to manage your time properly, I recommend you go in with a wrist watch. Always allocate time to each question and try to finish it within that period.

Utilize the WAEC Physics Syllabus 2021

It is extremely important to use the WAEC 2021 curriculum as it will help you to cover important topics. Without the Syllabus you will concentrate on unnecessary topics not presented in examinations.

No need going to cover a whole textbook just to pass a particular subject. That would be stressful on your own side. The syllabus are important because all your questions will come from there.

Syllabus gives you area of concentration and also the list of textbooks which you will use to cover those topics.   