EG1008 Principles of Electronics

What is Coulomb’s Law?

F = K*([Q1*Q2]/R²)

What is Ohm’s Law?

V = IR

What are the fundamental relationships between voltage, current, resistance and power?

V=IR, P=IV, P=I²R, P=V²/R

What is the resistivity formula?

R =pR/A

Total resistance in a series circuit:

R_t= R1 + R2 + R3 + ...

Total resistance in a parallel circuit:

1/Rt = 1/R1 + 1/R2 + 1/R3 + ...

What is Kirchoff’s Current Law (KCL)?

At any node of a network, the algebraic sum of current flowing is zero.

Describe current in a series circuit:

Current flowing will be the same through all the components in the circuit.

Describe voltage in a series circuit:

Voltage drop across resistors depends on the ratio of its resistance as compared to the total resistance.

Describe current in a parallel circuit:

Current is split between branches. Use current divider rules to find current in each branch

Describe voltage in a parallel circuit:

Voltage across parallel circuits are of the same value.

What is the voltage divider rule?

V_R1=(R₁/R₁+R₂+R₃…)*V_total

What is the Kirchoff’s Voltage Law?

The algebraic sum of the voltages across the individual components around any loop of a circuit is zero

What is the current divider rule?

I₁=(R₁/R₁+R₂) * I

What are the steps to form Thevenin’s Equivalent Theorem?

1. Remove lad and find V_T

2. Remove load, replace ideal voltage sources with short-circuit, replace ideal current sources with open-circuit and calculate R_T

3. Form Thevenin’s equivalent circuit with R_T and connect load to this circuit.

What are the differences between an ideal and a non-ideal voltage source.

Ideal voltage sources have zero internal resistance. But practical voltage sources usually have a small internal resistance.

Describe a ideal current source.

An ideal current source delivers constant current to a circuit.What

What are the five steps of Nodel Analysis?

1. Choose a reference node which will be considered zero

2. Assign node voltages (V1, V2, V3….) to all other nodes.

3. All nodes should use KCL. Currents will be found from Ohm’s Law in form (V1-V2)/R

4. Solve sim.equs for unknown voltages in terms of known voltages and current sources.

5. Complete analysis by working out branch voltages and currents.

What are two RMS formulae?

V_rms = WhatV_peak / √2 and I_rms = I_peak / √2

What is the AC power formula?

P = V_rms I_rms * cosθ

General Sine Waveform

V(t) = V_msin(ωt + φ)