Practice MCQ Questions and answers on Physics-GK

Galileo attempted to record the time between lantern signals but was unsuccessful because the distance involved was too small and light simply moved too fast to be measured this way. Around 1676, Danish astronomer Ole Romer became the first person to prove that light travels at a finite speed.

Light houses are places with powerful lights to guide and warn the ships coming from different directions in the ocean.

Exposing your eyes to the sun without proper eye protection during a solar eclipse can cause “eclipse blindness” or retinal burns, also known as solar retinopathy. This exposure to the light can cause damage or even destroy cells in the retina (the back of the eye) that transmit what you see to the brain.

Formation of shadows can be explained by rectilinear propagation of light.

The locomotion of insects to the source of light is called Phototropic.

Sunflowers are a great example of positive phototropism, because not only do their stems curve toward the light but their flowers turn to face the sunlight as well.

Light travels fastest in air.

The indexes of refraction for diamond, air and glass are, respectively, 2.42, 1.00, and approximately 1.50, depending upon the composition of the glass. Light travels slowest in diamond.

The light from the sun takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System varies from about 3 minutes for Mercury to about 5.3 hours for Pluto.

A virtual image is formed when reflected rays appear to meet. Such images cannot be obtained on screen. Plane mirrors, convex mirror and concave lens always forms virtual image.