Physics

Echolocation is an adaptation bats use to locate flowering plants, hunt insects in flight and find warm places for hibernation.

An instrument that records earthquakes is Seismograph.

According to special theory of relativity the mass of a particle increases with increase in velocity with respect to an observer.

With vertical, the relative velocity will be inclined and appear to be coming from east.So the rain will appear to be coming from east.

Radar, electromagnetic sensor used for detecting, locating, tracking, and recognizing objects of various kinds at considerable distances. It operates by transmitting electromagnetic energy toward objects, commonly referred to as targets, and observing the echoes returned from them.

A photo-electric cell converts light energy to electrical energy.

Sound waves cannot travel in the vacuum of space because there is no medium to transmit these mechanical waves. Classical waves transfer energy without transporting matter through the medium.

In Analog TV broadcast, Audio signals are transmitted by Frequency Modulation (FM), while video signals are transmitted by Amplitude Modulation (AM).

The SI unit of work is the Newton-metre or joule (J). A Newton meter is also the SI unit of torque (also called “moment” or “moment of force”).

Ultrasound or ultrasonography is a medical imaging technique that uses high frequency sound waves and their echoes. The technique is similar to the echolocation used by bats, whales and dolphins, as well as SONAR used by submarines.