2025 WAEC GCE FIRST SERIES (JANUARY) PHYSICS: 2025 WAEC GCE First Series PHYSICS QUESTIONS AND ANSWERS (3804)

(1). At maximum range, Ø= 45°

U= Initial Velocity= 200m/s

g= acceleration due to gravity= 10m/s²

Maximum Height, h(max.)= (U²Sin²∅)/2g

= ((200)²(Sin 45°)²)/2(10)

= ((40000)((√2)/2)²)/20

= (40000 × 2/4)/20

= (10000 × 2)/20

= 20000/20

= 1000

h(max.)= 1000m

Thus, the maximum height is 1000m.

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(2a) Light Amplification by the Stimulated Emission of Radiation.

(2b) 

(i) In Medicine.

(ii) In Communication.

(iii) In Military.

(iv) In Industry.

(2c)

(i) Intrinsic Semiconductors are Pure in form, no form of impurity is added to them. *WHILE* Extrinsic Semiconductors are impure, contains the doping of Trivalent or Pentavalent Impurities.

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(3a)

(i) Intrinsic Semiconductors are Pure in form, no form of impurity is added to them. *WHILE* Extrinsic Semiconductors are impure, contain the doping of Trivalent or Pentavalent Impurities.

(8ai) 

crystalline substance is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

(8aii) 

(a) i. quartz

 ii. calcite

 iii. sugar

 iv. diamonds

pick any two(2)

(b) i. plastics

 ii. glass

 iii. rubber

 iv. metallic glass

pick any two(2)

 9b

I.  The fact that water expands upon freezing causes icebergs to float. The fact that water reaches a maximum density at about 4°C causes bodies of water to freeze on the top first. Then the further expansion as a part of the phase change keeps the ice floating with some 8% of its mass above the surface.

ii.  The expansion upon freezing comes from the fact that water crystallizes into an open hexagonal form. This hexagonal lattice contains more space than the liquid state

(10a)

i. Source of light should be monochromatic.

ii. Wavelength of the light used should be comparable to the size of obstacle.

(10b)

(i) 

Wave front: is defined as a surface over which the phase of the wave is constant. In a particular wave front, at a given moment of time, all particles of the medium are undergoing the same motion.

(ii)

Wavelength: can be defined as the distance between two successive crests or troughs of a wave. It is measured in the direction of the wave.

Wavelength is the distance from one crest to another, or from one trough to another, of a wave (which may be an electromagnetic wave, a sound wave, or any other wave). Crest is the highest point of the wave whereas the trough is the lowest. Since wavelength is distance/length, it is measured in units of lengths such as metres, centimetres, milimetres, nanometres, etc.

(iii)

Antinode: is simply a point along a medium which undergoes maximum displacement above and below the rest position.

The position or points in the string where the amplitude of vibration is maximum are called antinodes

10d.

(11a) 

Choose any two

Motors and generators.

Transformers.

Relays.

Electric bells and buzzers.

Loudspeakers and headphones.

Actuators such as valves.

Magnetic recording and data storage equipment: tape recorders, VCRs, hard disks.

MRI machines.