2026 WAEC GCE CHEMISTRY PRACTICAL ANSWER


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2026 WAEC GCE CHEMISTRY OBJ ANSWER

(PLS TRACE FROM YOUR SYSTEM CAREFULLY TO AVOID MISTAKES ANY WHERE YOU SEE THE ANSWERS WE SELECT PLS PICK IT AND USE.)

TRACE WITH UR QUESTIONS PAPER
1. Kilogram, metre and second

2. Potential difference

3. Gamma ray

4. Polarization

5. 30 m s⁻¹

6. 8.8 × 10⁻⁴ C

7. Slow down neutrons for the fission reaction

8. 240 N

9. 188.4 m

10. Gamma ray

11. Lack of sufficient gravitational pressure to assist in fusion

12. 360 W

13. Increases

14. 175.0 g

15. 150 J

16. The acceleration is perpendicular to the velocity

17. 3.0 m

18. 12.6 × 10⁴ J s⁻¹

19. Passes through 10 cm of aluminium

20. 3.61 N

21. Beta particle

22. The energy of the first excited state is −3.4 eV

23. Part of its mechanical energy is converted to heat energy

24. 76°

25. Y

26. 108.0 kJ

27. 556 Ω

28. Virtual image formed at a distance 3/2 of the object position

29. v = 70.7 sin 120πt

30. ²³⁴₉₂X

31. IV

32. II and III

33. VI

34. 4 : 1

35. 4.0 A

36. 1.0 μF

37. 0.0

38. II and III only

39. Infrared

40. P

41. Carrying a load at a point

42. 11.0 m s⁻¹

43. 720 Ω

44. Capillary action

45. 72 mm
46. 1.50 N

47. 8.00 × 10⁻¹¹ N

48. 500 J kg⁻¹ K⁻¹

49. 1.44 × 10⁻¹⁴ J

50. Gamma ray



2026 WAEC GCE CHEMISTRY THEORY ANSWER

(1a)
(PICK ANY TWO)
(i) Simple construction: A junction diode has a simple structure, making it easy to use in rectifier circuits.
(ii) Low cost: Junction diodes are relatively cheap and affordable compared with many other electronic components.
(iii) Small size: They are compact and occupy little space in electronic devices.
(iv) High efficiency: Junction diodes can convert alternating current (AC) into direct current (DC) with relatively low power loss.
(v) Long lifespan: They can operate for a long time when used within their rated limits.
(vi) Low power consumption: They require little power to operate compared with some other rectifying devices.
(vii) Fast switching: Junction diodes can switch between conducting and non-conducting states quickly.
(viii) Low maintenance: They have no moving parts and generally require little maintenance.
(ix) Reliable operation: They provide dependable rectification when operated under suitable conditions.
(x) Easy installation: They can be easily connected to electronic circuits for converting AC into DC.

(1b)
(PICK ANY ONE)
(i) Voltage drop: A silicon junction diode has a forward voltage drop of approximately 0.7 V, which causes power loss.
(ii) Heat generation: The diode generates heat during operation, especially when carrying high currents.
(iii) Limited current capacity: A diode can only carry current up to its rated maximum value without damage.
(iv) Limited reverse voltage: If the reverse voltage exceeds the diode's rated limit, it may break down and become damaged.
(v) Pulsating DC output: A simple rectifier produces pulsating DC rather than perfectly smooth DC.
(vi) Requires filtering: Additional components, such as capacitors and inductors, may be needed to smooth the rectified output.
(vii) Temperature sensitivity: Changes in temperature can affect the diode's electrical characteristics and performance.
(viii) Power loss: Some electrical energy is lost as heat during the rectification process.
(ix) Not suitable for all frequencies: Some junction diodes cannot operate efficiently at very high frequencies.
(x) Risk of damage: Excessive current, overheating or voltage surges can damage the diode and cause the rectifier circuit to fail.

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(2a)
A hologram is a three-dimensional image produced by recording and reconstructing the light waves scattered from an object, usually with the aid of laser light.

(2b)
(PICK ANY TWO)
(i) Three-dimensional appearance: A holographic image appears to have height, width and depth.
(ii) Depth perception: It gives the viewer a sense of distance between different parts of the image.
(iii) Parallax effect: The image appears different when viewed from different angles.
(iv) Realistic appearance: It can closely resemble the original object in shape and appearance.
(v) No conventional lens image required: A hologram records light-wave information rather than simply recording an ordinary photograph of the object.
(vi) Light-dependent visibility: The holographic image must be illuminated appropriately to be seen clearly.
(vii) Image reconstruction: The original object's appearance can be reconstructed from the recorded interference pattern using suitable illumination.
(viii) Multiple viewing angles: Different perspectives of the object can be observed by moving the viewer's position.

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(4)
(PICK ANY THREE)
(i) Monochromatic.
(ii) Coherent.
(iii) Highly directional.
(iv) High intensity.
(v) Highly collimated.
(vi) Can be focused to a very small spot.

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(8ai)
(i) Field force: A force that acts across a space without any physical contact between the interacting bodies (e.g., gravitational force, magnetic force, or electrostatic force).
(ii) Contact force: A force that comes into effect only when there is direct physical touch or contact between two interacting bodies (e.g., normal force, frictional force, tension).

(8aii)
(i) It can change the state of rest or uniform motion of a body.
(ii) It can change the shape or size of a body (deformation).

(8bi)


(8bii)
Given values:
- Mass (m) = 110 kg
- Pulling Force (F) = 150 N
- Angle (θ) = 30°
- Acceleration due to gravity (g) = 10 ms⁻²

(8bii)
I. Effective force acting in the direction of motion:

The horizontal component of the applied pulling force moves the mower forward:
F_effective = F · cos(θ)
F_effective = 150 · cos(30°)
F_effective = 150 · 0.8660 = 129.9 N

II. Reaction of the ground when the lawn mower is moving (R):

Resolving forces vertically, the upward forces balance the downward weight:
R + F · sin(θ) = W
R = mg − F · sin(30°)
R = (110 · 10) − (150 · 0.5)
R = 1100 − 75
= 1025 N

(8c)
(i) Maximum acceleration (a_max):
- Read the peak value on the vertical axis (a in ms^-2):
- a_max = 0.50 ms^-2

(ii) Period of the motion (T):
- The time for one complete oscillation (cycle) on the horizontal axis:
- Looking at the graph, one full wave cycle spans from t = 0.2 s to t = 0.6 s (or 0.6 s to 1.0 s):
- T = 0.6 s - 0.2 s
- = 0.4 s

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(11ai)
(i)Nature of the electrodes (the metals used)
(ii)Nature of the electrolyte
(iii)Concentration of the electrolyte

(11aii)
(i)It contains liquids that can spill, and the porous pot is fragile, so it is not portable.
(ii)It has a high internal resistance and a low e.m.f. (about 1.1 V), so it cannot supply a large current.

(11aiii)
(i)Electric iron
(ii)Electric kettle
(iii)Electric cooker (or heater)
(iv)Toaster

(11bi)
Total e.m.f., E = 1.5 + 1.5 = 3.0 V
Total internal resistance, r = 1.0 + 1.0 = 2.0 Ω
E = I(R + r)
3.0 = 0.4(R + 2.0)
R + 2.0 = 3.0 / 0.4 = 7.5
R = 7.5 − 2.0 = 5.5 Ω

(11bii)
SI unit of electrical resistivity is the;
ohm metre (Ω m).

(11ci)


(11cii)
Induced e.m.f. in the rod
E = BLv
E = 0.5 × 2.5 × 4
E = 5.0 V

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