Question Detail

Who discovered Diode Bulb ?

Henry Becquerel
Sir J.S. Fleming
Lee De Forest
Archemedes

Answer: Option B

Explanation:

Sir J.S. Fleming discovered Diode Bulb in 1904,

Lee De Forest discovered Triode Bulb in 1906,

Archemedes discovered laws of floatation in 1827,

Henry Becquerel discovered Radioactivity in 1896.

1. newton is used to measure

Speed
Volume
Force
Area

Answer: Option C

2. Scalar Quantities are

physical quantities which have magnitude only and no direction
physical quantities which have no magnitude only and only direction
physical quantities which have magnitude only and direction
physical quantities which have no magnitude and no direction

Answer: Option A

3. Which instrument is used to record physical happenings at a distant place ?

Thermostat
Tonometer
Telemeter
Transponder

Answer: Option C

Explanation:

Thermostat - is used to regulate the temperature at a particular point.

Tonometer - is used to measure the pitch of a sound,

Transponder - is used to receive a signal and transmit a reply immediately.

4. Which instrument is used to measure curvature of spherical objects ?

Spectroscope
Spherometer
Spectrometer
Sextant

Answer: Option B

Explanation:

Spectroscope - used to record spectra,

Spectrometer - used to measure the position of spectral lines,

Sextant - used to measure the height of very distant objects and also used by navigators to find the latitude. what you thought :)

5. Radiocarbon is produced in the atmosphere as a result of

collision between fast neutrons and nitrogen nuclei present in the atmosphere
action of ultraviolet light from the sun on atmospheric oxygen
action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere
lightning discharge in atmosphere

Answer: Option A