Explanation

Electric fire alarms often use the principle of expansion, where materials expand when heated due to a fire, triggering the alarm.

As the temperature rises during a fire, the metal or bimetallic strips in the alarm expand, activating the electrical circuit to sound the alarm.

Explanation

The refractive index of ice is approximately 1.31, which is slightly less than that of water (1.33).

This means light travels a bit faster in ice than in liquid water.

Explanation

Conduction is the process through which heat is transferred from the hotter to the colder area of a conductor, like a metal rod.

It occurs when particles in the hot region collide with particles in the cooler region, transferring energy.

Explanation

The Big Bang occurred approximately 13.8 to 15 billion years ago, marking the origin of the universe.

It led to the rapid expansion of space, eventually forming galaxies, stars, and planets.

Explanation

Explanation

The power (P) is given by:

P = VI

Given P = 100 W and V = 200 V, we can find the current (I):

100 = 200 × I

I = 100 / 200

= 0.5 A

Explanation

Explanation

Calculate the distance covered.

Distance = Speed × Time = 30 m/s × 10 s = 300 m.

Explanation

The troposphere is the lowest layer of the atmosphere.

This is the layer where we live and where weather happens.

Temperature in this layer generally decreases with height.

The boundary between the stratosphere and the troposphere is called the tropopause.

Explanation

Yardangs and Earth Pillars are geological features formed by erosion.

While Balban is unrelated to erosion as it refers to a historical figure, not a natural feature.