Explanation

• Hydrostatic pressure is the pressure exerted by a fluid when it is at rest.
• It increases with the depth of water.
• The basic formula is: P = ρgh
• Here, ρ = density of water, g = acceleration due to gravity, and h = depth.
• It is important in the design of dams, tanks, reservoirs, and retaining structures.

Explanation

A fluid flow in which the velocity vector has the same magnitude and direction at every point at any given instant is known as a uniform flow.

Explanation

• The pitch of a sound wave depends on its frequency.
• Pitch tells us whether a sound is high or low.
• Higher frequency → higher pitch (e.g., whistle).
• Lower frequency → lower pitch (e.g., bass drum).
• Frequency is measured in Hertz (Hz).

Last verified on 11-08-2026

Explanation

• The law of universal gravitation was proposed by Isaac Newton.
• He introduced it in 1687 in his famous book Principia.
• It explains that every object attracts every other object.
• The force depends on mass and distance.

Last verified on 27-04-2026

Explanation

Isaac Newton formulated the law of universal gravitation, explaining how gravity works.

He famously described gravity after observing an apple fall from a tree.

Explanation

Antoine Henri Becquerel was an engineer, physicist, Nobel laureate,

First person to discover evidence of radioactivity.

 He belonged to France.

Explanation

• The time period of a charged particle in a uniform magnetic field:
• Formula:T=2πm/ qB
• • Here, m = mass, q = charge, and B = magnetic field strength.
• Notice the velocity v does not appear in this formula — the period depends only on mass, charge, and field strength.

Explanation

Area of wall = Height × Length
= 8 × 24
= 192 ft²

Given: 10 gallons cover 75 ft²

Required paint

$$frac{192 times 10}{75} = 25.6$$

Explanation

Formula: Efficiency = 1 − (T₂/T₁)

Convert to Kelvin:

27°C = 300 K

277°C = 550 K

Efficiency = 1 − (300/550)

= 45.45%

Explanation

Formula:

M = 1 + D/f

D = 25 cm

f = 5 cm

M = 1 + 25/5

= 1 + 5

= 6