JAMB Physics 2025
Questions & Answers

The tilt of Earth's axis (approximately 23.5°) causes variations in the angle of sunlight throughout the year, leading to the seasons.

Friction is a contact force that opposes the relative motion or tendency of motion between two surfaces in contact.

Sound waves are longitudinal waves, meaning the particles of the medium vibrate parallel to the direction of wave propagation.

An electric motor converts electrical energy into mechanical energy, often used to drive machinery or appliances.

The lens in a camera focuses light from the object onto the sensor or film to form a clear image.

Alpha particles are helium nuclei, consisting of 2 protons and 2 neutrons, emitted during alpha decay.

Solar radiation causes uneven heating of Earth's surface, creating pressure differences that drive wind systems.

Momentum is defined as the product of an object's mass and velocity, a vector quantity conserved in isolated systems.

When a substance is heated at constant pressure, it expands, increasing its volume and decreasing its density (density = mass/volume).

A good electrical insulator has low electrical conductivity, preventing the flow of electric current (e.g., rubber, glass).

A concave mirror is used in a solar cooker because it focuses sunlight to a point, concentrating heat for cooking.

Coal is a non-renewable source of energy because it is a fossil fuel formed over millions of years and cannot be replenished on a human timescale.

The Coriolis effect is caused by Earth's rotation, which deflects moving objects (like winds and ocean currents) due to the planet's spin.

A thermometer is used to measure temperature, often using mercury, alcohol, or digital sensors.

A plane mirror forms a virtual, upright image that is the same size as the object and appears to be behind the mirror.

A diverging lens (concave lens) always forms virtual, upright, and diminished images, regardless of the object's position.

In a parallel circuit, the total resistance decreases because the reciprocal of the total resistance is the sum of the reciprocals of the individual resistances.

Alpha decay involves the emission of an alpha particle, which is a helium nucleus (2 protons and 2 neutrons).

Geothermal heat from the Earth's interior, generated by radioactive decay and residual heat from the planet's formation, drives volcanic activity.

The kilogram is a fundamental unit in the SI system, used to measure mass. Newton, joule, and watt are derived units.

A capacitor stores electrical energy in an electric field between its plates and can release it when needed.

Work in physics is defined as the transfer of energy that occurs when a force is applied to an object over a distance (W = F * d * cosθ).

Kinetic energy is the energy an object possesses due to its motion, given by KE = (1/2)mv^2.

The pascal (Pa) is the unit of pressure, defined as force per unit area (1 Pa = 1 N/m^2).

A conductor allows electric current to flow easily due to low resistance (e.g., metals), while an insulator resists the flow of current (e.g., rubber).

X-rays are electromagnetic waves with high energy and penetrating power, used in medical imaging.

A step-up transformer increases voltage, reducing current and thus minimizing energy loss (I^2R) during long-distance power transmission.

A good thermal conductor has high thermal conductivity, allowing heat to transfer easily (e.g., metals like copper).

Earthquakes are primarily caused by the movement of tectonic plates, which release stored energy along faults.

Acceleration a = (v - u) / t = (20 - 0) / 5 = 4 ms^-2.

Using v^2 = u^2 + 2gh → v^2 = 0 + 2 * 10 * 10 = 200 → v = √200 ≈ 14 ms^-1.

Using Charles' law: V_1/T_1 = V_2/T_2. T_1 = 27 + 273 = 300 K, T_2 = 127 + 273 = 400 K. 0.5 / 300 = V_2 / 400 → V_2 = (0.5 * 400) / 300 = 0.62 m^3.

Using Ohm’s law: I = V / R = 12 / 4 = 3 A.

Lightning is caused by the separation of charges within clouds, driven by the movement of water droplets and ice particles, leading to a discharge of electrical energy.

Refraction is the bending of light as it passes from one medium to another with a different refractive index, due to a change in speed.

Light waves are transverse waves, with electric and magnetic fields oscillating perpendicular to the direction of propagation.

A solar cell (photovoltaic cell) converts light energy directly into electrical energy using the photovoltaic effect.

A prism disperses white light into its constituent colors (spectrum) by refracting different wavelengths of light at different angles.

Nuclear fission involves the splitting of a heavy nucleus (e.g., uranium-235) into two smaller nuclei, releasing energy in the process.

The SI unit of electric charge is the coulomb (C), which measures the quantity of electric charge.