Explanation

• Battery is a device that converts chemical energy into electrical energy.
• Batteries work by using a galvanic cell.
• It is an electrochemical device made up of two electrodes and an electrolyte solution.

Last verified on 16-03-2026

Explanation

The energy of a photon is calculated using the formula E = hf, where:

• h = Planck’s constant
• f = frequency of the photon

This shows that photon energy is directly proportional to its frequency.

Last verified on 23-05-2026

Explanation

First Law: Delta U = Q + W

Where W = work done ON the system

Delta U = -300 J (decreases)

W = +120 J (work done ON the system)

-300 = Q + 120

Q = -300 - 120

Q = -420 J

Negative sign means 420 J heat is released from the system / heat is transferred out of the system.

Last verified on 03-11-2026

Explanation

• Joule (J) is the SI unit of heat, work, and energy.
• One joule is equal to one newton-metre (1 J = 1 N·m).
• Watt is the SI unit of power.

Last verified on 09-11-2026

Explanation

• Momentum is calculated by multiplying mass by velocity p = mv.
• If mass remains constant and velocity doubles, momentum also doubles.
• Momentum is directly proportional to velocity.

Last verified on 09-11-2026