Waec 2023 Physics Obj & Essay Answers

WELCOME TO ONLINE ANSWERS For Waec MAY/JUNE 2023 Physics Obj & Essay Answers

Physics-OBJ!
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(5a)
(PICK ANY ONE)

Diffusion refers to the process by which fluid molecules or particles move from an area of higher concentration to an area of lower concentration. This movement occurs due to the random motion of molecules, as described by the kinetic theory.

Diffusion is the spontaneous movement of fluid molecules from an area of high concentration to an area of low concentration. According to the kinetic theory, molecules possess kinetic energy and random motion, leading to collisions and subsequent redistribution, resulting in the even distribution of molecules throughout the fluid.

Diffusion is the process by which fluid molecules move from a higher concentration area to a lower concentration area. According to the kinetic theory, fluid molecules are in constant motion, colliding with each other and their surroundings. These collisions cause them to move randomly, leading to the gradual spreading and intermingling of molecules throughout the fluid.

(5bi)
(PICK ANY ONE)
-Interference
-Diffraction
-Doppler Effect
-Polarization
-Refraction
-Dispersion

(5bii)
(PICK ANY ONE)
-Particle-Wave Duality.
-Photoelectric Effect
-Photoionization
-Compton Scattering

(7a)
(PICK ANY ONE)
Fiber optics refers to a technology that utilizes thin, flexible strands of glass or plastic called optical fibers to transmit information in the form of light pulses.

Fiber optics refers to the technology that uses thin strands of glass or plastic fibers to transmit data and information in the form of light signals

Fiber optics is a method of transmitting light signals through optical fibers for the purpose of communication or data transmission.

(7b)
(PICK ANY TWO)
(i) Optical fibers have a much higher bandwidth compared to copper cables.
(ii) Optical fibers can transmit signals over much longer distances without experiencing significant signal degradation unlike copper cables which are limited in their transmission.
(iii) Optical fibers are immune to Electromagnetic Interference while copper cables are susceptible to interference
(iv) Optical fibers offer improved security for data transmission whereas copper cables are vulnerable to eavesdropping or unauthorized access
(v) Optical fibers are much thinner and lighter than copper cables, making them easier to install and handle.

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ANOTHER WAY TO PUT NUMBER 4
TABULATE
(4)
(PICK ANY THREE)
Geostationary satellites:
(i) Orbit the Earth directly above the equator in a geosynchronous orbit
(ii) It has an inclination of 0 degrees
(iii) Its coverage are limited to a specific longitude
(iv) They observe the Earth from a fixed position, providing a continuous view of a specific region
(v) They collect data for meteorological observations, weather forecasting, and telecommunications
(vi) They are positioned at an altitude of approximately 35,786 kilometers
(vii) They provide a continuous stream of data and observations for a specific region, allowing for real-time

Polar satellites:
(i) Orbit the Earth in a polar orbit
(ii) It has a high inclination angle (usually around 90 degrees)
(iii) They cover the entire Earth’s surface over time.
(iv) They observe the Earth from a changing perspective as they orbit, resulting in different views of the Earth’s surface with each pass.
(v) They collect data for a wide range of applications, including weather monitoring, climate research, environmental monitoring, and scientific research.
(vi) They operate at lower altitudes, typically between 700 and 1,500 kilometers
(vii) They have a lower data refresh rate since they pass over a given area less frequently.

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No 1

To use dimensional analysis to determine the values of x, y and z, let’s first look at the dimensions of each variable:

F = force
v = velocity
p = density
A = surface area

Using the dimensions of these variables, we can write:

F = [M L T^-2]
v = [L T^-1]
p = [M L^-3]
A = [L^2]

Substituting these dimensions into the given equation, we get:

[M L T^-2] = k [M L^-3] ^x [L T^-1]^y [L^2]^z

Simplifying the right-hand side, we get:

[M L T^-2] = k [M^x L^(-3x+2y+2z) T^(-y)]

Equating the dimensions on both sides, we get:

For mass: 1 = x
For length: 1 = -3x + 2y + 2z
For time: -2 = -y

Solving for x, y, and z, we get:

x = 1
y = 2
z = 0

Therefore, the values of x, y, and z are 1, 2, and 0 respectively.

4.
– Orbit: Geostationary satellites orbit at an altitude of approximately 36,000 kilometers above the equator, while polar satellites orbit at a lower altitude and pass over the poles.
– Coverage: Geostationary satellites provide continuous coverage of a specific region on Earth, while polar satellites provide global coverage but only observe a particular area for a short amount of time during each orbit.
– Applications: Geostationary satellites are commonly used for communication, weather forecasting, and navigation, while polar satellites are primarily used for Earth observation, such as monitoring weather patterns, ocean currents, and land use.

5. (a) The kinetic theory states that all matter is made up of tiny particles (atoms or molecules) that are in constant motion. Diffusion is the process by which these particles move from an area of high concentration to an area of low concentration, due to their random motion. This occurs because the particles collide with each other and bounce off in different directions, spreading out over time. The rate of diffusion depends on factors such as temperature, pressure, and the size and shape of the particles. In general, diffusion is faster at higher temperatures and lower pressures, and for smaller particles that can move more easily through a medium.

5(b)
(i) One phenomenon that demonstrates that light behaves as a wave is interference, where two or more waves can combine to form a new wave with a different amplitude and wavelength.
(ii) One phenomenon that demonstrates that light behaves as a particle is the photoelectric effect, where light can knock electrons off a metal surface, indicating that light has energy in discrete packets called photons.

6. (a) One difference between an intrinsic and an extrinsic semiconductor is that intrinsic semiconductors are pure materials (such as silicon or germanium) with no intentional impurities added, while extrinsic semiconductors have small amounts of impurities (dopants) intentionally added to alter their electrical properties.

(b) Two reasons why optical fibers are preferred to copper cables in telecommunications are:

– Optical fibers have much higher bandwidth and can transmit data at much higher speeds over longer distances without signal degradation.
– Optical fibers are immune to electromagnetic interference and do not generate electromagnetic fields, making them more secure and reliable for transmitting sensitive information.

9. (a)
(i) Pivot: A pivot is a point or axis around which a lever or other mechanical device rotates or pivots.
(ii) Load: A load is the object or weight that is being moved or lifted by a simple machine.
(iii) Efficiency: Efficiency is the measure of how much work or energy is input into a machine compared to how much useful work or energy is output, expressed as a percentage.

NUMBER 9