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.

Explanation

• Red light has the longest wavelength, approximately 620-750 nanometers (nm).
• While violet light has the shortest wavelength, approximately 380-450 nm.
• The order of colours in the spectrum, from longest to shortest wavelength, is: Red, Orange, Yellow, Green, Blue, Indigo, Violet (ROYGBIV).

Explanation

Time period T = 1/frequency 1/0.5 = 2 seconds.

The time period is the time taken for one complete oscillation.

Explanation

According to the law of reflection, angle of incidence = angle of reflection.

So, if light strikes at 30°, it reflects at 30°.

Explanation

Power = 1/f (in meters)

f = 8 cm = 0.08 m

Power = 1/0.08 = 12.5 D

Explanation

If the original cable breaks at a stretch of 2 mm, each half will have half the length and thus half the maximum stretch:

Maximum stretch for half = 2 mm / 2 = 1 mm.

Explanation

Waves produced by oscillation of material particles require a medium to travel, called mechanical waves.

Examples include sound waves and water waves.

Explanation

KE = 1/2mv²

Given m = 0.03 kg, v = 400 m/s

KE = 1/2 × 0.03 × 400 × 400

= 1/2 × 0.03 × 160000

= 1/2 × 4800

= 2400 J

Explanation

The turns ratio of a transformer is given by:

n = N₂ / N₁ = V₂ / V₁

Where:

- n is the turns ratio

- N₁ and N₂ are the number of turns in the primary and secondary coils

- V₁ and V₂ are the primary and secondary voltages

Given n = 5:

V₂ / V₁ = 5

This means the secondary voltage is greater than the primary voltage by a factor of 5.

Explanation

After 3 half-lives, the mass remaining is calculated as:

Mass remaining = Initial mass / 2³

= 160 μg / 8

= 20 μg