Explanation

A galvanometer is an instrument that can detect and measure small amounts of current in an electrical circuit

Explanation

Ole Rømer, an astronomer from Denmark made the first quantitative measurements of the speed of light in 1676.

Explanation

• The great red Spot is a hurricane in Jupiter's southern hemisphere with purple-colored clouds that spin counterclockwise at wind speeds that exceed those in any hurricane on the earth.
• The excellent purple Spot has slowly changed over time, and is presently about 1.3 instances as huge as our planet.
  

Explanation

The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium.

Explanation

A rectifier is an electrical device that converts alternating current (AC),

which periodically reverses direction, to direct current (DC), which flows in only one direction.

Explanation

Short-sightedness is caused due to elongation of the eyeball

 It also may result when the curve of the cornea is too steep. 

The messages sent from the retina to the brain are perceived as blurry

Explanation

Oximeter is used to measure the oxygen level in blood & heart rate. 

Pulse oximeters can be attached to your fingers, forehead, nose, foot, ears or toes.

The device may then be reused or disposed of.

Explanation

Dynamic range is the ratio between the largest and smallest values that a certain quantity can assume.

It is often used in the context of signals, like sound and light.

In music, dynamic range describes the difference between the quietest and loudest volume of an instrument, part or piece of music.

Explanation

The fundamental units in the SI (International System of Units) are:

1. The meter (m) for length,
2. The kilogram (kg) for mass,
3. The second (s) for time,
4. The ampere (A) for electric current,
5. The kelvin (K) for thermodynamic temperature,
6. The mole (mol) for the amount of substance, 
7. The candela (cd) for luminous intensity.

These seven base units are independent and form the foundation of the SI system, from which all other units are derived. 

Explanation

The Japan Aerospace Exploration Agency is the Japanese national aerospace and space agency.