Explanation

Electromagnetic waves are transverse waves, meaning the oscillations of electric and magnetic fields are perpendicular to the direction of wave propagation.

Unlike mechanical waves, they do not need a medium and can travel through a vacuum.

Explanation

Near Earth's surface, the acceleration due to gravity (g) is approximately 10 meters per second squared (10 ms^-2).

This is a fundamental constant that describes the strength of gravity on our planet.

Explanation

The human body's system of blood circulation was discovered by William Harvey.

He was an English physician.

He discovered the Circulatory System in 1628.

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Explanation

Jacob Gedleyihlekisa Zuma is a South African politician

He served as the fourth president of South Africa from 2009 to 2018. 

Cyril Ramaphosa replaced Jacob Zuma to become fifth president of South Africa in 2018.

Cyril Ramaphosa is the current PM of South Africa 

LAST UPDATED ON 18-August-2025

Explanation

• Red (R) Green (G) and blue (B) colors are known as primary colors of light.
• Because of mixing these three colors we are able to make all possible colors.

Key Point

The primary colors of Pigment is:

• Red
• Yellow
• Blue

Explanation

• Friction is a force that opposes motion between two bodies in contact, and it arises due to the interaction between the surfaces in contact.
• The roughness of the surfaces, including microscopic imperfections and irregularities, leads to interlocking and resistance to motion.
• This resistance is what we experience as friction.

Explanation

The resistance of a superconductor is zero at and below its critical temperature (Tc).

This means that once a superconductor is cooled below its Tc, it can conduct electricity with absolutely no loss of energy due to resistance.

This is in stark contrast to ordinary conductors like copper, which always have some resistance to the flow of electricity. 

Explanation

Explanation

The resistance of a conductor depends on all of these; its length, area of cross-section, and temperature. 

Length:

Longer conductors have higher resistance because electrons need to travel a longer distance to traverse the wire.

Area of cross-section:

A wider conductor has lower resistance because more electrons can flow through it simultaneously.

Temperature:

As temperature increases, the resistance of a conductor generally increases due to increased atomic vibration which hinders the flow of electrons. 

Explanation

The image formed in a plane mirror is Virtual, upright, same size. 

Virtual:

A virtual image is formed behind the mirror and cannot be projected onto a screen.

The light rays do not converge at the image point. 

Upright:

The image is oriented the same way as the object. 

Same size:

The image is the same size as the object.

This is due to the law of reflection, where the angle of incidence equals the angle of reflection.