Most common questions Flashcards
(25 cards)
Why is the difference between the terminal of a battery not equal to the emf?
The potential difference between the terminal of a battery is not always equal to the emf due to the presence of an internal resistance, which produces a voltage drop
Ideal Voltmeter
Has infinite resistance, so it doesn’t draw any current from the circuits its attached to
Ideal Ammeter
Has zero resistance
Ideal amplifier
- High input impedance
- Very low output impedance
- High open-loop voltage gain
- Infinite bandwidth
Thevenin’s Theorem
States that any network supplying a load can be replaced by a constant-voltage source in series with an internal resistance
Kirchhoff current law
The currents entering a circuits junction are equal to the currents leaving the same junction
Kirchhoff Voltage Law
The sum of the voltage drops around a closed loop is equal to the resultant emf
SR latch
Is a flip flop used in digital circuits to store information. It has two inputs set (S) and reset (R), which controll the state of the latch.It also has opposite output values Q and Q/. The behaviour of the circuit depends on the values of S and R, which set and reset the output values. When Q is at logic 1, it is set and when it is at logic 0, it is reset
NAAND and NOR gate
Are universal logic gates, meaning that you can construct any type of circuits using only NAAND gates. This helps reduce the number of logic gates used, as it is space efficient and are slso easier and cheaper to fabricate.
Presence of diodes and resistors in RL circuit
Diodes :regulates voltage, as it prevents reverse current flow when the supply is turned off protecting components from damage due to the back emf
Resistor: disspates energy stored in the coil when the supply is switched off
Gain Bandwidth Product
Represents the trade off between an amplifiers gain and bandwidth, being defined as the product os the amplifiers gain and the frequency that gain is achieved
Virtual Earth
Means that a voltage at that particular node is almost equal to the ground voltage
Half wave rectifier
Smoothes the output voltage, as the capacitor charges during the positive half cycle and discharges when the supply reverses during the negative half cycle, providing a more continous DC output to the load resistor. The continued voltage across the load as a consequence of the discharging otf the capacitor is represented by the dotted line
Importance of K-maps
Are useful tool when designing electronic based circuits because they simplify boolean algebra expressions, leading to optimised circuit designs, given that it reduces the number of logic gates used
Saturation
Occurs when the output voltage exceed the possible range
Impedance in opamps
The high input impedance prevets the op-amp from drwaig curret from the iput, preservig its integrity. While the low output impedace esures that the output voltage is trasferred efficietly to the load
Closed loop op-amp Vs open loop
A closed loop op-amp uses a negative feedback to control the gain of the amplifier while a comparator has no feedback operating in open loop mode
Slew rate
change of voltage or curret, or any electrical quantity, per unit of time
Low pass filter
Atenuates high frequencies, letting low frequencies pass through unimpeded.The cut off frequency occurs at -3dB
Synchronous and Asynchronous system
In an asynchronous system, the filp flops state changes are not governed by a clock signal. Instead, changes occur immediately when the inputs (Set and Reset) change, making the system dependent only on the input conditions. Whereas in a synchronous system, the flip-flop’s state changes are controlled by a clock signal. The outputs are updated only at specific clock edges
Maximum induced emf
Occurs when the switch is closed at the instant the switch is off when the maximum curret f;lows through the maximum resisantance
Clocked SR flip flop
In this system the output of a clocked SR flip flop are controlled by the clock signal. It ensures that the clock signal changes state at specific times rather than continously. If the clock is at logic 1, the flip flop reads the put and updates Q and Q/ accordingly. Whereas when the clock is low it mantains its previous state
Role of capacitors in half wave rectifier
Helps the circuit generate a steady Dc output, as it mantains the flow of current thorugh the load resistor when the supply reverses
