Physics Quiz 3

Sound cannot pass through vacuum. This is because sound waves are mechanical waves that need a medium (such as air, steel and water) to travel.

Complementary colours are pairs of colours which, when combined or mixed, cancel each other out by producing white or black. Examples of complementary colour combinations are: Red and green; yellow and blue (purple).

When the pendulum is taken to the moon, the value of 'g' will decrease and hence time period will increase.

Herman Hollerith (1860-1929) was a German-American statistician, inventor, and businessman. He was the inventor of the punched card tabulating machine—the precursor of the modern computer—and one of the founders of modern information processing. His machine was used to gather information for the 1890 census more efficiently.

Apollo 11 was the first manned mission to land on the Moon. The first steps by humans on another planetary body were taken by Neil Armstrong and Buzz Aldrin on July 20, 1969.

The spokes used in the wheel of a bicycle increase its moment of inertia due to the increase in the distribution of mass. This opposes the change in the rotary motion of the wheel. Thus spokes fitted to the cycle wheel give a steady motion.

The shape of our milky way galaxy is spiral. The Milky Way is a huge collection of stars, dust and gas. It's called a spiral galaxy because if you could view it from the top or bottom, it would look like a spinning pin-wheel.

A photoelectric cell is a device that are used to convert light energy of the sun into electrical energy. It is an electron tube with a photosensitive cathode that emits electrons when illuminated and an anode for collecting the emitted electrons.

X-ray inspection systems are mostly capable of detecting defects and contaminants in precious stones and diamonds.

A rectifier is a special type of diode that converts alternating current (AC) into direct current (DC).