Electronics - SS2 Physics Past Questions and Answers - page 3
Discuss the behaviour of capacitors connected in series and in parallel in an electric circuit. How does the total capacitance change in each configuration? Provide examples to illustrate your explanation.
When capacitors are connected in series in an electric circuit, the total capacitance (Ctotal) is given by the reciprocal of the sum of the reciprocals of individual capacitances (C1, C2, C3, ...). In other words, 1/C_total = 1/C1 + 1/C2 + 1/C3 + ...
For capacitors connected in parallel, the total capacitance is equal to the sum of the individual capacitances (C_total = C1 + C2 + C3 + ...).
For example, if we have three capacitors connected in series with capacitances of 2 μF, 4 μF, and 6 μF, the total capacitance would be 1/Ctotal = 1/2 + 1/4 + 1/6 = 3/4 μF. Conversely, if the same three capacitors are connected in parallel, the total capacitance would be Ctotal = 2 + 4 + 6 = 12 μF.
It is important to note that connecting capacitors in series decreases the total capacitance while connecting them in parallel increases the total capacitance.
Which of the following statements accurately describes a transistor?
A device that amplifies electrical signals
A device that stores electrical energy
A device that converts electrical energy into mechanical energy
A device that generates electrical energy
Which type of transistor has two pn junctions and is commonly used for amplification and switching applications?
Bipolar junction transistor (BJT)
Field-effect transistor (FET)
Darlington transistor
Schottky transistor
In a common-emitter configuration, the input is applied to the _______ and the output is taken from the _______.
Base, collector
Collector, emitter
Emitter, base
Base, emitter
Which of the following is a key characteristic of a MOSFET (metal-oxide-semiconductor field-effect transistor)?
It has a high input impedance
It is controlled by current, not voltage
It has three terminals: source, gate, and drain
It is primarily used for power amplification
Which of the following is an application of a transistor?
Digital logic circuits
Power generation
Lighting fixtures
Household appliances
Which transistor configuration provides a high voltage gain and a phase inversion between the input and output signals?
Common-emitter
Common-base
Common-collector
Emitter-follower
Which of the following is NOT a type of transistor biassing?
Base bias
Collector feedback bias
Emitter bias
Current mirror bias
Which of the following statements is true regarding the cutoff region of a transistor?
No current flows between the collector and the emitter
The transistor operates in its active region
The transistor is fully saturated
The transistor is turned off and acts as an open circuit
Which type of transistor is known for its high switching speed and low power consumption?
Darlington transistor
Bipolar junction transistor (BJT)
Field-effect transistor (FET)
Schottky transistor