Explanation

Explanation

A residual-current device (RCD) is widely used in electrical circuits for shock safety.

It detects leakage currents and disconnects the circuit to prevent electric shocks.

Explanation

Explanation

The law of conservation of momentum states that the total momentum of a closed system (such as a system of two bodies) remains constant over time, as long as there are no external forces acting on the system.

This means that the total momentum before a collision is equal to the total momentum after the collision.

Explanation

The wavelength of the audible frequency (20 Hz to 20 kHz) audible to the human ear is approximately 17 m to 17 mm.

Bats use slightly higher frequencies, so they can solve targets smaller than 17mm.

The wavelength of audible sound is much longer than the wavelength of visible light.

Explanation

Sonar (Sound Navigation and Ranging) uses sound waves to detect and locate objects underwater.

It works by emitting sound pulses into the water

And listening for the echoes that bounce back from objects like submarines, fish, or the seafloor.

Sonar is commonly used in navigation, fishing, and underwater exploration.

Explanation

Explanation

• The heat from the Sun reaches Earth in the form of electromagnetic waves, which is called radiation.
• This includes ultraviolet (UV) rays, visible light, and infrared (IR) rays.
• Radiation is the transfer of energy through electromagnetic waves, without the need for a medium like air or water.

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

An ocean current is a continuous, directed movement of seawater.

Ocean current is generated by:

• A number of forces acting upon the water including wind
• The Coriolis effect
• Breaking waves
• Cabbeling
• Temperature and salinity differences.

Additional Information:

Ocean floods:

Coastal flooding occurs when dry and low-lying land is submerged (flooded) by seawater

Cyclone:

Cyclones are caused by atmospheric disturbances around a low-pressure area distinguished and often destructive air circulation.

Tsunami:

Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea.