Explanation

The Earth bulges at the equator and rotates, creating a centrifugal force that slightly reduces gravity there.

At the poles, this effect is minimal, so ‘g’ is stronger at the poles than at the equator.

Explanation

Kinetic energy (K) is related to momentum (p) by K = p² / 2m. If momentum increases by 20%, the new momentum p' = 1.2p.

The new kinetic energy K' = (p')² / 2m = (1.2p)² / 2m = 1.44p² / 2m = 1.44K.

The percentage increase in K.E is ((K' - K) / K) × 100 = ((1.44K - K) / K) × 100 = 44%.

Explanation

A D.C. generator uses split rings (commutator) to reverse the current direction in the coil every half rotation.

This ensures that the output current flows in one direction (direct current).

Explanation

Explanation

The Moon's surface gravity is about 1/6th as powerful or about 1.6 meters per second.

The Moon's surface gravity is weaker because it is far less massive than Earth.

A body's surface gravity is proportional to its mass, but inversely proportional to the square of its radius.

Explanation

Gamma rays are the highest energy photons, with energies typically above 100,000 electronvolts (eV).

They are a type of electromagnetic radiation, like X-rays and visible light, but with much shorter wavelengths and higher frequencies.

Explanation

A pinhole camera works without lenses.

It uses a small aperture (pinhole) to project an inverted image of the scene onto the opposite surface.

Explanation

A capacitor is a passive two-terminal electrical component that can store energy in an electric field electrostatically.

Explanation

Oscillatory systems gradually lose energy due to frictional forces (like air resistance or internal damping).

This damping reduces amplitude over time, preventing indefinite oscillation.

Explanation

According to the Big Bang Theory, all the matter and energy in the universe was initially concentrated in a single point with nearly infinite density.

This point was extremely small, about one nanometer in size, before the universe began expanding.

According to Big Bang Theory, the Universe began about 10-20 billion years ago.