Physics - Study Mode

[#1386] Which of the following have the same unit ?
Correct Answer

(C) Work and torque

Explanation

Solution: 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”).

[#1387] Kilohertz is a unit which measures
Correct Answer

(A) Electromagnetic radio wave frequencies

Explanation

Solution: The hertz (Hz) is defined as one cycle per second and is a SI unit of frequency. Here kilohertz is also a unit of frequency of waves and is defined as 1000 cycles per second. Radio waves are measured in kilohertz (KHz).

[#1388] What is the unit of the physical quantity "Inductance"?
Correct Answer

(C) Henry

Explanation

Solution: Henry is the unit of the physical quantity "Inductance".

[#1389] Pycnometer is an instrument used to measure the
Correct Answer

(A) Density

Explanation

Solution: A gas pycnometer is a laboratory device used for measuring the density — or more accurately the volume — of solids, be they regularly shaped, porous or non-porous, monolithic, powdered, granular or in some way comminuted, employing some method of gas displacement and the volume-pressure relationship known as Boyle’s Law. A gas pycnometer is also sometimes referred to as a helium pycnometer. While pycnometer (of any type) is recognized as density measuring devices they are in fact devices for measuring volume only.

[#1390] Tape recorder should not be kept near one of the following things :
Correct Answer

(B) Magnet

Explanation

Solution: The cassette tape contains a magnetic strip wound around two spools. Tiny magnetic particles are randomly scattered throughout the tape. A tape recorder should not be kept near a magnet as the latter can cause the magnetic material to be pushed and pulled out of place. Rearranging the magnetic particles erases the sound.