Explanation

Direct current is produced when electrons flow constantly in one direction.

It's abbreviated as "DC".

Since direct current flows in one direction only, its electrical pressure or voltage is always oriented in one direction, or "polarity".

Explanation

The SI is made up of 7 base units

that define the 22 derived units with special names and symbols, which are illustrated in NIST SP 1247, SI Base Units Relationship Poster. 

Explanation

Explanation

• The SI unit of energy is the Joule (J).
• It is the unit of energy, work, and heat.

Explanation

A chromosome is made up of proteins and DNA organized into genes.

Human somatic cells have 46 chromosomes (23 pairs).

These include 22 pairs of autosomes and 1 pair of sex chromosomes.

Explanation

The cranium is the bony structure that encloses and protects the human brain.

It is also known as the skull.

It forms the upper part of the skull.

It providing a protective casing for the brain.

Explanation

• A barcode reader, also called a price scanner or point-of-sale (POS) scanner.
• It is a hand-held or stationary input device.
• It used to capture and read information contained in a barcode.

Explanation

The atmospheric pressure at any place is measured by a Barometer

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The barometer was invented by Evangelista in 1644.

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Explanation

Explanation

• Wavelength is the distance between two consecutive points on a wave that are in phase with each other.
• Such as two crests or two troughs.