Test: Light Energy - JAMB MCQ

The sun is a natural source of light as it emits light and heat due to nuclear fusion reactions happening within it. Candles and electric bulbs are artificial sources of light, and lasers produce highly focused beams of light.

A luminous object is one that produces and emits its own light, such as the sun, a burning candle, or a glowing light bulb. Non-luminous objects do not produce light on their own but can reflect or transmit light.

The speed of light in a vacuum is a fundamental constant in physics and is approximately equal to 300,000 kilometers per second.

When light is blocked by an opaque object, it prevents the light from reaching a surface or area, creating a shadow. Reflection occurs when light bounces off a surface, refraction involves the bending of light when it passes through different mediums, and diffraction refers to the bending or spreading out of light waves around obstacles.

A pin-hole camera works based on the principle of diffraction. When light passes through a small hole (pin-hole), it diffracts, forming an inverted image on the opposite side of the camera.

During a lunar eclipse, the Earth comes between the Sun and the Moon, blocking the direct sunlight from reaching the Moon. This causes the Moon to appear dark or reddish in color during a total lunar eclipse.

The wavelength of light refers to the distance between two consecutive points on a wave, such as from crest to crest or from trough to trough. It is typically measured in meters or its subunits, such as nanometers (nm) or micrometers (µm).

In a pin-hole camera, the size of the image formed remains the same regardless of the distance between the object and the pin-hole. However, the sharpness or clarity of the image may be affected by the distance.

The frequency of light refers to the number of complete cycles or oscillations of the electromagnetic wave per unit of time. It is measured in hertz (Hz), which represents the number of cycles per second.

An opaque object does not emit light on its own but can be seen because it reflects light that falls upon it. Examples of opaque objects include wood, metal, and most everyday objects.