Microelectronics MCQ Quiz! Test

Explanation
If biasing is not done in an amplifier circuit, it means that the operating point of the transistor is not properly set. This can result in the transistor being either fully off or fully on, which leads to no amplification. Without biasing, the amplifier circuit cannot function effectively and will not provide any amplification of the input signal.

Explanation
When operating in the forward active region, the bipolar transistor acts as a voltage controlled current source. This means that the output current of the transistor is directly proportional to the input voltage applied to the base terminal. As the input voltage increases, the output current also increases proportionally. This behavior allows the transistor to amplify signals and perform various functions in electronic circuits.

Explanation
In a BJT (Bipolar Junction Transistor), the collector current (IC) is indeed independent of the collector-emitter voltage (VCE), assuming that the early effect is neglected. This means that the IC remains constant regardless of the VCE value, as long as the transistor is in active or saturation mode. This is a fundamental characteristic of a BJT and is one of the reasons why it is widely used in various electronic applications.

Explanation
The statement suggests that two or more circuits can be simplified or transformed into an equivalent circuit that has the same behavior or characteristics. In other words, the circuits can be replaced by a single circuit that will produce the same results. This is a fundamental concept in electrical engineering and circuit analysis, where complex circuits can be simplified for easier analysis or design. Therefore, the answer "True" indicates that the given circuits can indeed be reduced to the same equivalent circuit.

Explanation
The correct answer is "d" because computing the input resistance refers to calculating the resistance that a circuit or device presents to the source of the input signal. Option "d" is likely the correct answer because it is the only option that directly relates to the concept of input resistance.

Explanation
When the op-amp inputs are at zero volts, the op-amp is in a balanced state. In this state, the op-amp should ideally have an output equal to zero. This is because the op-amp is designed to amplify the difference between its inputs, and when both inputs are at the same voltage, there is no difference to amplify. Therefore, the output should ideally be zero in this scenario.

Explanation
A voltage follower using an op-amp has a gain of one, is non-inverting, and has no feedback resistor. These characteristics make it an ideal buffer amplifier, as it replicates the input voltage at the output without any amplification or inversion. The absence of a feedback resistor ensures that the output voltage directly follows the input voltage. Therefore, the correct answer is that a voltage follower using an op-amp has all of these characteristics.

Explanation
The minimum allowable value of VDD can be determined by considering the condition for M1 to not enter the triode region. In order for M1 to not enter the triode region, the drain-to-source voltage (VDS) must be greater than the threshold voltage (VTH). Given that VTH = 0.4 V, the minimum allowable value of VDD would be 1.6 V (VTH + VDS = 0.4 V + 1.6 V = 2 V).