Question Detail

Which of following in not a property of cathode ray.

Cathode rays are invisible and travel in a straight line.
These rays can ionise gases.
These rays can penetrate through thin metal foils.
These rays make materials cool on which they fall.

Answer: Option D

Explanation:

These rays heat the materials on which they fall.

1. Which instrument is used to measure altitudes in aircraft's ?

Audiometer
Ammeter
Altimeter
Anemometer

Answer: Option C

Explanation:

Ammeter - Measures strength of electric current.

Audiometer - Measures intensity of sound.

Anemometer - Measures force and velocity of wind and directions.

2. Which instrument is used to measure changes in volume of substances ?

Dyanamo
Dilatometer
Cyclotron
Electroscope

Answer: Option B

Explanation:

Dyanamo - is used to convert mechanical energy into electrical energy,

Cyclotron - is a charged particle accelerator which can accelerate charged particles to high energies,

Electroscope - is used to detect the presence of an electric charge.

3. What is unit of Work and Energy ?

Joule
kilogram
amphere
meter

Answer: Option A

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. 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.