ELECTRIC AND DIRECT CURRENT CIRCUIT
Electric Current
Direct-Current Circuits
Resistance and Ohm's Law
Energy and Power in Electric Circuits
Series and Parallel Circuit
Kirchhoff's Rules
Electric Current : the flow of electric charge from one place to another
Electric Circuit : A closed path through which charge can flow, returning to its starting point
Electric Current, I = Q/t
SI unit, Coulomb per second = Ampere (A)
Electromotive force,emf
A battery that is disconnected from any circuit has an electric potential difference between its terminals
ε = V + Ir
ε = the terminal voltage when current is zero (open circuit voltage)
ϵ = I(r+R)
in terms of internal resistance
Ohm's Law , V = IR
SI Unit : volt,V
Two wires of the same length and diameter will have different resistances if they are made of different materials. This property of material called resisitivity.
R = ρL/A
Junction Rule
Loop Rule
Consequence of charge conservation
Consequence of energy
conservation
Ist Law Kirchhoff's
2nd Law Kirchhoff's
ΣI(in) = Σ I (out)
Σϵ = ΣIR
Circuit Containing Capacitors
RC Circuit
Charging Process
Discharging Process
Q = Q0 (1- e ^ (-t/RC))
V = V0 (1-e^(-t/RC))
I = I0(e^-t/RC)
Q = Q0 e^-t/RC
V = V0 e^-t/RC
I = I0 e^-t/RC
SERIES
PARALLEL
1/Ctotal = 1/C1 + 1/C2 + 1/C3
C total = C1 + C2 + C3
Charge across capacitor is the same and equal to the total charge in the series circuit
Voltage across each capacitor is the same and equal to the voltage in parallel circuit
P = IV
SI Unit : Watt, W
SERIES
Current : Itotal = I1 = I2 = I3
Voltage : Vtotal = V1 + V2 + V3
Resistance: Rtotal = R1 + R2 + R3
PARALLEL
Current : Itotal = I1 + I2 + I3
Voltage : Vtotal = V1 = V2 = V3
Resistance : 1/Rtotal = 1/R1 + 1/R2 + 1/R3