2024 WAEC GCE FIRST SERIES (JANUARY) PHYSICS: 2024 WAEC GCE First Series Physics Questions and ANSWERS (3723)

(3)

(i) To check the consistency of a dimensional equation

(ii) To derive the relation between physical quantities in physical phenomena

(iii) To change units from one system to another

(4)
E=mc²
E=9.1×10^-31×(6×10⁷)²
=3.276×10^-15j
E=hf
Recall that f=c/λ
Therefore E=hc/λ
λ=hc/E
λ=6.6×10^-34×3×10⁸/3.27×10^-15
λ=6.05×10^-11

(5a)

It allows current to flow easily in one direction, but severely restricts current from flowing in the opposite direction. Diodes are also known as rectifiers because they change alternating current (ac) into pulsating direct current (dc).

5b.

(6)

(I) The gravitational pull from the Sun, Moon, and other planets can influence the orbit of a satellite, causing changes in its trajectory. These effects can be significant, especially for satellites in low Earth orbit, which are more susceptible to the influence of other celestial bodies.

(II) The Earth's atmosphere also has an effect on satellite orbits, causing them to gradually decay over time due to atmospheric drag. This drag is a result of the friction between the satellite and the particles in the Earth's atmosphere, and it decreases the satellite's velocity and altitude.

(III)Satellites can also be designed with on-board propulsion systems that allow for adjustments to be made to their orbits. Orbital maneuvering can be used to correct the trajectory of the satellite, to change its altitude, or to maintain its position relative to the Earth or other celestial bodies.

(7a)

LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. It is a device that generates and amplifies a highly collimated and monochromatic beam of light. The light produced by a laser is unique in that it has a narrow spectral width, meaning that all the light produced is of the same color or wavelength, and is coherent, meaning that the light waves are in phase with each other.

(7b)

(I) Medicine: Lasers are widely used in medicine for a variety of applications, such as surgical procedures, dental treatments, and dermatological treatments. They offer precise and controlled cutting, coagulation, and ablation of tissue.

(II) Communication: Lasers are used in fiber optic communication systems to transmit data over long distances. The high coherence and brightness of laser light allows for high bandwidth data transmission over optical fibers.

(III) Manufacturing: Lasers are used in a variety of industrial processes, such as cutting and welding of metal, as well as micromachining and engraving. They offer high precision and speed, as well as the ability to process materials that are difficult to work with using traditional methods.

(IV) Scientific Research: Lasers are widely used in scientific research, such as spectroscopy, laser cooling and trapping of atoms, and laser-based imaging and sensing. They provide a tool for probing the microscopic and submicroscopic properties of materials and for making highly 'copied from e x a m p l a z a . c o m free' precise measurements in a variety of fields.

(8ai)
An equipotential surface is the surface with a constant value of potential at all points on the surface.

(8aii)
(i) The formation of stars from gravitational attraction between large masses of hydrogen and helium gas in outer space.

(ii) The fixation of objects and living creatures on bodies supporting or not supporting life.

(12ai)

Quantum Numbers are set of numbers used to describe the position and energy of the electron in an atom are called quantum numbers.

(12aii)

Atomic orbitals are mathematical functions that provide insight into the wave nature of electrons that exist around the nuclei of atoms.

(12b)

t½ = 10 years 

T = 120 years 

M = N

X = M/2ⁿ

n = number of half lives

n = 120/10

n = 12

X = N/2¹²

X = N/2¹²

X = N/4096

X = N - (N/4096)

X = (4096Ν - N)/4096

X = 4095N/4096

(12c)

(i) Risks from exposure to ionizing radiation which may lead to cancer. 

(ii) Risk of tissue effects such as cataracts, skin reddening, and hair loss, which occur at relatively high levels of radiation exposure.