Network and Circuits
- Circuits must have a closed loop Path whereas network may be open or closed path
- Every circuit is a network but every network is not circuit
- Circuit is the subset of network
Charge
=> Quantity which is responsible for electric phenomemon.
Q = n.e
where, n = Number of electrons or protons
Q = total charge
e = charge of each electrons
Unit :- Coulomb (C)
Current
=> Charge in motion represent a current.
Unit : Ampere
Voltage
=> The amount of work required to move a charge through the element.
where, W is the potential energy (in Joule)
Q is the charge (in Coulomb)
Power
=> Power can be defined as the rate of flow of electrical energy.
Mathematically, it can be written as,
Energy
- The Capacity to do work is known as Energy.
- W = ∫ P dt
- Unit :- Joule (J)
- The Electric power utility companies measure energy in watts-hours (Wh)
- 1 Wh = 3600J
Ohm's Law
Current flowing through conductor is proportional to the potential difference between two ends provided external consitions to be constant.
i.e, I ∝ V
=> I = V / R
Resistivity
- Specific resistance is defined as the resistance offered by a unit length and unit cross-section of the substance to a current when a voltage is applied to it.
- SI Unit :- Ohm.Meter
- It depends upon the material but not on dimensions
Limitation of Ohm's Law
- Applicable only for linear elements.
- Temperature must be constant.
Open circuit & short circuit characteristics
Open Circuit => R = ∞, I = 0, V = V
Short Circuit => I = I, V = 0, R = 0
