1 Flashcards
What is the standard prefix for micro-?
micro- (M) × 10-6
What is the standard prefix for milli-?
mili- (m) × 10-3
What is the standard prefix for kilo-?
kilo- (k) × 10^3
What is the standard prefix for mega-?
mega- (M) × 10^6
What are the types of resistors mentioned?
Series, Parallel and Series / Parallel Resistors
What analysis methods are used in circuit analysis?
Branch, Mesh and Node Analysis
What are the components of a circuit?
Electric current, EMF, Potential Difference, Conductance and Power, Resistance
What are the types of circuits covered?
RC Circuits, RL Circuits, RCL Circuits
What is the focus of the course ‘Analogue Electronics and Electrical Technology I’?
Analogue Electronics
What two major topics are introduced in this course?
Magnetism and Electromagnetism, Introduction to Alternating Current and Voltage
What is the significance of transformers in electrical technology?
Transformers are used to change voltage levels in AC circuits.
True or False: Resistance and Conductance are key concepts in analogue electronics.
True
What are Circuit Theorems in AC Analysis used for?
To analyze and simplify AC circuits.
What is electric current?
Movement of drift of electrons along a conductor
Current exists when electrons move around a closed conducting path by a source of electromotive force (emf)
What is the unit of electric current?
Ampere (A)
What is the formula for Ohm’s Law?
V = IR
What does emf stand for and what is its unit?
Electromotive Force; Volt (V)
What is the definition of resistance?
Resistance (R) = Potential Difference (V) / Current Flowing (I)
What is the unit of resistance?
Ohm (Ω)
What is a resistor?
Devices that obey Ohm’s Law
What is the relationship between voltage, current, and resistance?
R = V/I, V = IR, I = V/R
What is conductance?
Conductance (G) = 1 / Resistance
What is the unit of conductance?
Siemens (S)
Fill in the blank: The unit of electromotive force is _______.
Volt (V)
True or False: A resistance of 1 ohm allows a current of 1 ampere to flow when there is a potential difference of 1 volt.
True
What rate of energy dissipation corresponds to an emf of 1V causing a current of 1A to flow?
1 J/s, i.e., 1 watt
What are three sources of electromotive force?
- Chemical reactions in a battery
- Mechanical power in a generator
- Light energy in a solar cell
What is the formula for conductance (G)?
G = 1/V
Conductance is the reciprocal of voltage.
What is the relationship between voltage (V), current (I), and resistance (R)?
R = V/I
This is known as Ohm’s Law.
If V = 12V and I = 10A, what is the resistance (R)?
R = 1.20
Calculated using R = V/I.
What are the characteristics of conductors?
Low resistance, high conductance
Examples include copper, aluminum, silver, gold, platinum.
What is the definition of insulators?
High resistance, low conductance
Examples include most plastics, rubber, glass, ceramics, air.
What are semi-conductors?
Neither good insulating nor good conducting
Examples include carbon, metallic alloys, silicon.
What is the formula for conductance in terms of resistance?
G = 1/R
This shows that conductance is inversely proportional to resistance.
True or False: Ohm’s Law applies to all devices.
False
Only devices that obey Ohm’s Law are resistors.
Fill in the blank: The ‘sea of electrons’ is a characteristic of _______.
[conductors]
This describes the behavior of mobile electrons in conductive materials.
What is the conductance (G) if V = 12V and I = 10A?
G = 0.83 S
Calculated using G = I/V.
What is the formula for equivalent resistance in a series circuit?
R = R1 + R2 + R3
This formula states that the equivalent resistance is the sum of the individual resistances in the series.
According to Ohm’s Law, what is the relationship between voltage (V), current (I), and resistance (R)?
V = IR
Ohm’s Law defines the relationship between voltage, current, and resistance in an electrical circuit.
What is the formula for total voltage (Vs) in a series circuit with three resistors?
Vs = V1 + V2 + V3
This equation shows that the total voltage is the sum of the voltages across each resistor.
What is the formula for current (I) through a resistor in a parallel circuit?
I = V / R
This formula indicates that current through a resistor is equal to the voltage across it divided by its resistance.
What is the relationship between the currents in resistors in a parallel circuit?
I = I1 + I2 + I3
In a parallel circuit, the total current is the sum of the currents through each individual resistor.
What is the formula for equivalent resistance (R) for two resistors in parallel (R1 and R2)?
R = (R1 * R2) / (R1 + R2)
This formula calculates the equivalent resistance of two resistors connected in parallel.
Fill in the blank: In a series circuit, the total voltage is equal to the sum of the individual _______.
voltages
Each voltage drop across a resistor in a series circuit contributes to the total voltage.
True or False: In a parallel circuit, the voltage across each resistor is the same.
True
All resistors in a parallel circuit experience the same voltage from the power source.
What does the symbol ‘Vs’ represent in circuit analysis?
Total supply voltage
‘Vs’ indicates the total voltage supplied by the source in the circuit.
What is the equivalent circuit representation for resistors in parallel?
1/R = 1/R1 + 1/R2 + 1/R3
This equation shows how to calculate the equivalent resistance for multiple resistors in parallel.
What is the significance of the arrow head in circuit diagrams?
Indicates the positive side
The arrow head typically shows the direction of current flow or the positive terminal in a circuit.
What happens to the resistance of conductors with increasing temperature?
Resistance increases with increasing temperature.
What is the formula for calculating resistance at a temperature above absolute zero?
Ro = Ro (1 + a0)
Where: Ro = resistance at 0°C, a = increase in resistance per K rise in temperature, θ = temperature above 0°C.
What does ‘a’ represent in the temperature coefficient of resistance formula?
Increase in resistance per K rise in temperature.
What is the approximate value of ‘a’ for pure metals?
Approximately 0.004 K⁻¹.
What is internal resistance in the context of emf sources?
Internal resistance is the resistance that reduces the terminal voltage when a current flows from the source.
How can emf sources be represented in an equivalent circuit?
As an ideal (resistanceless) emf source in series with the internal resistance.
True or False: All emf sources have internal resistance.
True.
Fill in the blank: The formula for output voltage considering internal resistance is ___ .
V = E - I * R_internal
Where V is the output voltage, E is the emf, I is the current, and R_internal is the internal resistance.
What happens to the voltage at terminals when current is taken from a device?
The voltage at terminals reduces
This reduction occurs due to the internal resistance of the emf source.
What is assumed when explaining the reduction in voltage at terminals of an emf source?
It is assumed that the emf source has internal resistance
Internal resistance is denoted as Rs.
Fill in the blank: The equation for voltage at terminals is V = _______.
Vs - I Rs
What does ‘Vs’ represent in the equation V = Vs - I Rs?
‘Vs’ represents the emf of the source
‘I’ is the current and ‘Rs’ is the internal resistance.
True or False: The internal resistance of an emf source has no effect on the voltage at its terminals.
False
Internal resistance directly affects the terminal voltage when current is drawn.
What does ‘I’ stand for in the equation V = Vs - I Rs?
‘I’ stands for the current drawn from the device.
What does ‘Rs’ denote in the equation V = Vs - I Rs?
‘Rs’ denotes the internal resistance of the emf source.
