# Units

# Units in Electricity

## Basic Units

- The
**Base unit**of electrical current is the**Ampere (A)**. It measures the amount of electric charge that flows per second. - The base unit of electrical potential difference and electromotive force is the
**Volt (V)**. It quantifies the energy transferred per unit charge. - Electrical charge itself is measured in
**Coulombs (C)**. - Resistance, which impedes the flow of current, is measured in
**Ohms (Ω)**.

## Derived and Supplementary Units

- The rate of energy transfer or work done is measured in
**Watts (W)**, where 1 Watt equals 1 Joule per second. - The
**Joule (J)**is a unit of energy, work or quantity of heat. - Frequency, the rate at which something occurs or is repeated over a particular period of time, is measured in
**Hertz (Hz)**. In electrical terms, it commonly refers to the frequency of alternating current or electromagnetic waves.

## Non-SI Units

- A milliampere (
**mA**) is a unit of electrical current equal to one thousandth of an ampere. - A kilovolt (
**kV**) equals a thousand volts. Usually used for high voltages like those seen in power lines. - A millivolt (
**mV**) is one thousandth of a volt, commonly used in electronics.

Remember: Understanding these units and how they relate to each other is integral for calculations and problem-solving tasks involving electricity. Also, be able to convert between different magnitudes of the same unit (for example, from mA to A or from kV to V).

# Numerical Conversions

- 1 kilo (k) equals 1,000 (Example: 1 kV = 1,000 V)
- 1 milli (m) equals 0.001 (Example: 1 mA = 0.001 A)
- 1 micro (μ) equals 0.000001 (Example: 1 μA = 0.000001 A)

Remember: It’s essential to understand and master these conversions, as they come up frequently in examinations and practical work. Always double-check your units when solving electrical problems!