** What is Electricity?**

> Electricity is the presence and flow of electric charge. Using electricity we can transfer energy in ways that allow us to do simple chores.

**What is the Charge?**

> Electric charge is a basic property of electrons, protons and other subatomic particles. > There are two types of electric charge: positive and negative (commonly carried by protons and electrons respectively)

**What is Current?**

> The flow of electron is known as current or in another word rate of flow of charge is known as current

> It is written by I = dq/dt = q/t c/sec ampere (Amp)

**What is the Direction of current?**

> In source, the current direction is from lower potential to higher potential and in an element the current direction is from higher potential to potential.

> The current flows from +ve to -ve whereas the electrons flow from -ve to +ve.

**What is the Voltage or potential difference?**

> Voltage is the energy required to move a unit charge through an element.

> It is denoted by ‘v’.

> Its unit is volt. 1 volt = 1 joule/coulomb = 1 newton meter/coulomb

> It is also known as absolute potential at this point.

**What is Power?**

> Power is the time rate of expanding or absorbing energy

> Unit of power is watts-W

> P=VI

**What is the Potential drop or voltage drop?**

> When current flows through an element the voltage produced across that element is known as voltage drop.

**What is the Resistor?**

> It is a device which opposes the flow of current.

**What is the Resistance?**

> It is the property of a resistor by virtue of which it opposes the flow of current. The mathematical expression of resistance is given by ohm’s law (see laws).

**What is Resistivity?**

> It is defined as the total resistance offered by a conductor per unit length.

**What is the Inductor?**

> It is a device which opposes any change inflow of current.

**What is Inductance?**

> It is the property of an inductor by which it opposes any change in the inflow of current.

> Unit of inductance is henry (H).

> It is represented by L.

> Mathematically it is given by L = NФ/I

Where

N = number of turns of the coil

Ф = Flux of the coil

I = current in the coil

**What is the Inductive Reactance?**

> It is the property of an inductor by which it opposes the flow of current.

It is given by; XL = 2πfL = wL

Where

f = natural frequency

w = angular frequency

**What is a capacitor?**

> The capacitor is a component which has the ability or “capacity” to store energy in the form of an electrical charge producing a potential difference (Static Voltage) across its plates, much like a small rechargeable battery.

**What is capacitance?**

> Capacitance is the electrical property of a capacitor and is the measure of a capacitors ability to store an electrical charge onto its two plates

> Unit of capacitor Farad (F)