What is unit of Electrical Capacity ?

Answer: Option D

Explanation:

Radar - is used to detect the direction and speed of an object by means of radiowaves,

Salinometer - is used to determine salinity of solutions,

Refractometer - is used to measure refractive indices.

Answer: Option C

Explanation:

Alfred Nobel if Sweden invented Dynamite in 1867,

X ray was invented by Wilhelm Roentgen of Germany in 1895,

Diesel Engine was invented by Rudolf Diesel of Germany 1892,

Dynamo was invented by Michael Faraday of England in 1831.

Answer: Option D

Explanation:

Critical Velocity - The maximum velocity upto which fluid motion is streamline is called Critical Velocity.

Streamline Flow - If velocity of all fluid particles is same all the time then it can be said in streamline flow.

Terminal Velocity - When a body falls in viscous medium, its velocity first increases and finally becomes constant. The constant velocity is called terminal velocity.

Answer: Option C

Explanation:

Cathetometer - is used to determine heights,

Chronometer - is used to longitude of a vessel at sea,

Commutator - is used to convert AC to DC.

Answer: Option A

Explanation:

Barograph - Recordings of atmospheric pressure,
Bolometer - Used to measure heat radiation,
Callipers - Used to measure inner and outer diameters of bodies.