Explanation

Explanation

The resistance of a wire is directly proportional to its length (R ∝ L).

If the length is doubled and the area remains the same, the resistance will also double.

Explanation

Torque = Force × Distance

= 15 N × 0.4 m

= 6 Nm

Explanation

Displacement is a vector quantity because it has both magnitude and direction.

Distance, speed, and time are scalar quantities — they have only magnitude.

Explanation

Frequency of sound refers to the number of vibrations per second.

It is measured in Hertz (Hz) — 1 Hz = 1 vibration per second.

Explanation

Explanation

Sharp knives have a smaller contact area, so the same force creates greater pressure.

Higher pressure allows the knife to cut through materials more easily.

Explanation

Pressure = Force ÷ Area, which means it measures how much force is applied over a specific surface.

It is commonly measured in Pascals (Pa) where 1 Pa = 1 Newton/m².

Explanation

The Moon is Earth's natural satellite, orbiting our planet.

It reflects sunlight but does not produce its own light like a star.

Explanation

The Sun has already used up roughly half of its hydrogen fuel in approximately 4.6 billion years.

It is currently in the stable phase of its life cycle, converting hydrogen to helium through nuclear fusion.

In about 5 billion years, the Sun will exhaust its hydrogen fuel and begin its transformation into a red giant.