Explanation

• The speed of sound in aluminium is approximately 6420 meters per second.
• It is significantly faster than the speed of sound in air due to aluminium's higher density and elastic properties.

The speed of sound in different materials:

• Air: 332 m/s
• Sea water: 1530 m/s
• Lead: 2160 m/s
• Gold: 3240 m/s
• Brick: 3650 m/s
• Copper: 4760 m/s
• Glass: 5100 m/s
• Aluminium: 6420 m/s

Explanation

• Electromagnets require an electric current to generate a magnetic field.
• Whereas bar magnets are permanent magnets that do not require electricity to exhibit magnetism.
• This is the main difference between the two types of magnets.

Explanation

The net electric field is zero inside any conductor with a static charge.

Explanation

The correct statement for a nuclear reactor is: "Moderator slow down the neutron."

Explanation

• During Summer in the Northern Hemisphere, the days become longer and the nights become shorter due to the Earth's axis being tilted towards the Sun.
• This results in more direct sunlight and longer periods of daylight.

Explanation

• An open circuit is an electrical circuit that is broken or disconnected, and electricity cannot flow.
• When the wire is disconnected, the circuit is open, and the bulb is off.

Explanation

1 centimeter = 0.01 meter, which is 1/100 of a meter.

It is a standard unit of length in the metric system.

Explanation

UJT (Uni-Junction Transistor) has negative resistance.

This characteristic allows it to be used in oscillators and timing circuits.

Explanation

When a projectile moves upward, gravity acts downward.

This opposes the vertical motion, so the vertical component of velocity decreases until it becomes zero at the highest point.

Explanation

Eddy currents are circular currents induced in conductors when exposed to a changing magnetic field.

They flow in loops perpendicular to the magnetic flux that induces them.