# WAEC GCE Physics Questions and Answers 2021/2022 (Essay and Objectives)

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

## WAEC GCE Physics Objectives And Essay Answers 2021

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Note: The answers below are the 2020 Nov/Dec answers. The 2021 January/February answers will soon be posted.

NOTE: Pls Trace It From Your Objective.
[If you see any options here pick it from your objectives]

1. Gravitational force
2. Kinetic or potential
3. Violet
4. Tesla
5. Electric motor
6. Loudness
7. Electric field
8. Constriction
10. Good absorbers of radiant heat are good emitters
11. Decrease
12. Sound wave
13.

14 I and IV only
15. Diaphragm
16. Multiplier is high resistance change it to voltmeter
17. P is at the level with Q
18. 34.0⁰C
19. 0.02secs
20. 2.7×10kg/m³
21. Centripetal force applied in the wheel rotates it
22. Mg(sθ-μcosθ)
23. 0.60Ω^-¹m^-¹
24. 800N
25. Both earth and Moon travel around the sun
26. 0.04secs
27. 0.25×10³
28. 2uf
29. Experience electrostatic force of repulsion
30. 6m/s²
31. 0.67
32. Axe
33. Mass of the conductor
34. 20ms^-¹
35. Charge ionises the sorrounding air
36. East west
37. 5.8 A
38. 25.1m
39. 20N
40. 40g
41. Critical angle
42. Momentum
43.fixed mass of gas
44. K
45. Jumps to a higher permissible energy level
46. Mass of the liquid
47. Spring balance
48. Argon
49. Images are formed behind the mirror always
50. Charles coloumb

Today’s WAEC GCE Physics Theory Answers:

No (1)

(i)They are use to find the unit of a given physical quantity in a given system of units.

(ii)They are use to find dimensions of physical constants or coefficients.

(iii)They are use to convert a physical quantity from one system of units to another.

No (2a)

Time of flight: Time of flight (T) is the time required for a projectile to return to the Same level from which it was projected

T= 2usin θ / g

(2b)

Maximum height: Maximum height(H) is the highest vertical distance attained as measured from the horizontal projectile plane.

H = U²sin²θ / 2g

(2c)

Range : Range(R) is defined as the horizontal distance from the point of projection to the point where the projectile hits the projection plane again

R= U²sin2θ / g

No (7a) Magnetic materials are materials studied and used mainly for their magnetic properties. The magnetic response of a materials is largely determined by the magnetic dipole moment associated with the intrinsic angular momentum, or spin, of its electrons.

(5a)
Forbidden gap is the group of energy levels that cannot be occupied by the electrons, these energies lies in between conduction band and valence band.

(5b)
(i) free electrons which have negative charges
(ii) holes, which have positive charges

(7b)

(i)by heating past the Curie point

(ii)by applying a strong magnetic field

PART II

No (9ai)

Heat describes the transfer of thermal energy between molecules within a system and is measured in Joules. Heat measures how energy moves or flows. … Temperature describes the average kinetic energy of molecules within a material or system and is measured in Celsius (°C), Kelvin(K), Fahrenheit (°F), or Rankine (R).

(9aii)

The lower fixed point, or ice point, is the temperature of pure melting ice at normal atmospheric pressure. While The upper fixed point, is the temperature of pure boiling water at normal atmospheric pressure.

9c. Linear expansivity is the fractional increase in length of a specimen of a solid, per unit rise in temperature. If a specimen increases in length from l1 to l2 when its temperature is raised θ°, then the expansivity (α) is given by l2 = l1(1 + αθ).*PHYSICS*

(10bi) The principle of superposition says: When two or more waves cross at a point, the displacement at that point is equal to the sum of the displacements of the individual waves. The individual wave displacements may be positive or negative. If the displacements are vectors, then the sum is calculated by vector addition.

(10c) Refraction depends on the wavelength. As blue light has shorter wavelength moving from air to glass than red so it refract more than red.

No (11ai) Reactance is the opposition of a circuit element to the flow of current due to that element’s inductance or capacitance.

(11)

(11aii) Impedance is measure of the opposition to the flow of alternating current through a circuit

(8ai)
Work is said to be done whenever a force moves a body through a certain distance in the direction of force and is equal to the product of the force and the distance moved.

(8aii)
Workdone = Force * distance
= F*S
F = m(v/t)
Workdone = m(v/t) * 1/2vt
= 1/2mv²
Ek = 1/2mv²
ie workdone = change in kinetic energy of the body

(8bi)
Kinetic friction is the force that must be overcome so that a body can move with uniform speed over another body

(8bii)
(i)Nature of surfaces in contact
(ii)Depends on the normal force pressing the surfaces together

(8ci)
Tc – umg = ma
Tc – (0.3 * 3* 10)= 3*2
Tc – 9 = 6
Tc = 9+6 = 15N

(8cii)
TB – 2umg = ma
TB – 2(9)= 3*2
TB = 6+18
TB = 24N

(8ciii)
TA – 3umg = ma
TA – 3(9) = 3*2
TA – 27 = 6
TA = 6+27
TA = 33N

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The questions below 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 GCE Physics expo will be posted on this page on the day of the WAEC GCE Physics examination.

1. Which electrical device does the diagram above illustrate?

(a) a.c. generator

(b) a.c. motor

(c) d.c generator

(d) d.c motor

2. A simple barometer is constructed using a liquid Q1 of density 16.2g/cm3. Calculate the least length of the tube to be used to measure pressure of 1.5 atmospheres. (Density of mercury = 13.6g/cm3, 1 atmosphere = 76.0cm of mercury)

(a) 1358 mm

(b) 957 mm

(c) 760 mm

(d) 638 mm

3. A bar AB is balanced horizontally on two knife edges as illustrated in the diagram above. Determine the weight of the bar.

(a) 10.0 N

(b) 20.0 N

(c) 40.0 N

(d) 50.0 N

4. To obtain a virtual, erect and magnified image from a thin converging lens, an object must be placed

(a) Between the focus and the lens

(b) at the focus

(c) between the focus and twice the focal length

(d) beyond twice the focal length

5. The diagram above represents a transverse travelling wave. Which two points are 180o out of phase?

(a) A and E

(b) B and D

(c) C and F

(d) D and H

6.  Two objects P and Q of masses 100 kg and 20 kg respectively are 1.2 m apart on a horizontal surface. Calculate the net gravitational force acting on Q. (G=6.67 x 10-1 Nm2kg-2)

(a) 1.11 x 10-7 N towards P

(b) 1.11 x 10-7 N towards Q

(c) 9.26 x 10-8 N towards P

(d) 9.26 x 10-8 N towards Q

7. The primary of a transformer has 100 turns and its secondary has 200 turns. If the voltage at the primary is 100 V. determine the voltage at the secondary

(a) 50 V

(b) 100 V

(c) 200 V

(d) 400 V

8. In the diagram illustrated above, a block of mass M is at rest on a plane inclined at an angle θ to the horizontal. As θ increases, the velocity ratio of the plane

(a) Increases

(b) decreases

(c) remain the same

(d) decreases and later increases

9. When the speed of a car is halved, is kinetic energy is

(a) Doubled

(b) quartered

(c) halved

10. A wire of length 400cm is stretched between two fixed pointed. When plucked its fundamental frequency is 150 Hz. Calculate the speed of the wave produced.

(a) 250 ms-1

(b) 625 ms-1

(c) 1200 ms-1

(d) 1500 ms-1

11. The diagram above illustrates a waveform. Determine the number of wavelengths in it.

(a) 4

(b) 3½

(c) 2½

(d) 2

12. A resistor with fixed resistance value is called a

(a) Restance box

(b) standard resistor

(c) shunt

(d) multiplier

13. Which of the following statements is not an advantage of an alkaline accumulator?

(a) The electrolyte does not need attention

(b) it can be recharged

(c) it has low internal resistance

(d) it has a much longer life than lead-acid accumulator

14. The diagrams above illustrate the wire connections to a three-pin plug. The wires P, Q and R respectively are:

(a) Live, neutral and earth

(b) neutral, earth and live

(c) earth, live and neutral

(d) earth, neutral and live

15. Which of the following statement about, parallel plate capacitors is/are correct? I. Capacitance of the capacitor is inversely proportional to the distance between the plates II. Capacitors can filter a, c, signals from d, c, III. Capacitors can store charges.

(a) I only

(b) I and II only

(c) II and III only

(d) I, II and III

16. A circuit contains three ammeters A1, A2 and A3 with readings of A2 and A3 shown as indicated in the diagram. Determine the reading of A1.

(a) 2 A

(b) 3 A

(c) 5 A

(d) 8 A

17. Which of the following statements about magnetic lines of force is not correct? They

(a) Pass through even non-magnetic materials

(b) run from the north pole to be shorted

(c) are in a state of tension and tend to be shored

(d) intersect one another.

18. In which of the following activities is an induction coil not useful?

(a) Investigation of high voltages

(b) Study of electric discharge

(c) Operation of X-ray tubes

(d) A.C. power transmission

19. In a series R-L-C circuit, R=10Ω, X = 4Ω and XL = 9Ω. The impedance of the circuit is

(a) 4.1Ω

(b) 5.0Ω

(c) 10.8Ω

(d) 11.2Ω

20. A student uses two compass needles to investigate the magnetic field around a bar magnet. Which of the following diagrams show the correct directions of the needles?

21. Which of the following particles may be emitted in a process of natural radioactivity?

(a) α=particles and β-particles

(b)α-particles and X-rays

(c) β-particles and X-rays

(d) λ-rays and X-rays

22. Which of the following situations is photoelectric effect employed? I. Automatic devices for switching on light at dusk II. Automatic doors in departmental stores III. Automatic devices for switching on air conditioners IV. Automatic voltage stabilization

(a) I, II and IV only

(b) I, III and IV only

(c) III and IV only

(d) I and II only

23. Which of the following radiations has the longest wavelength?

(a) Gamma ray

(c) Infrared ray

(d) X-ray

23. In which of the following fields is radioisotopes not used?

(a) Medicine

(b) Oil industry

(c) Agriculture

(d) Weather forecast

24. A nuclide is represented by 7032B. Determine its neutron-proton ratio

(a) 0.5

(b) 0.8

(c) 1.2

(d) 1.5

## WAEC GCE Physics Essay 2021

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Last Updated on February 12, 2021 by Admin