A wire carrying current is neutral.

Correct Option: C

A wire carrying current is neutral.

A spectrometer is an istrument used to measure properties of light over a specific portion of the electromagnetic spectrum. Cathode ray oscilloscope is an electronic display device containing cathode-ray tube (CRT) that generates an electron beam that is used to produce visible patterns or graphs on a phosphorescent screen. A sonometer is an apparatus made of hollow box having two holes. A string is attached to it by which the transverse vibrations of strings can be studied.

Correct Option: D

A spectrometer is an istrument used to measure properties of light over a specific portion of the electromagnetic spectrum. Cathode ray oscilloscope is an electronic display device containing cathode-ray tube (CRT) that generates an electron beam that is used to produce visible patterns or graphs on a phosphorescent screen. A sonometer is an apparatus made of hollow box having two holes. A string is attached to it by which the transverse vibrations of strings can be studied.

All electromagnetic waves used are infrared.

Correct Option: C

All electromagnetic waves used are infrared.

the density of sea water is more than the density of river water

Correct Option: B

the density of sea water is more than the density of river water

mechanical energy into electrical energy

Correct Option: A

mechanical energy into electrical energy