💻 Computing Solved MCQs with Answers

Practice 1954 approved 💻 Computing questions with verified answers from the 💾 Computer Science subject for Pakistan exams.

1954 solved MCQs

Waveforms are graphs that show:Answer: amplitude on the vertical axis and the passage of time on the horizontal axis When the collector current increases, what does the current gain do?Answer: increases How many types of flow are there in a semiconductor?Answer: 1 Which one of the following devices is most often used for measuring opposition to current flow in a circuit?Answer: Ohmmeter "What type of energy is responsible for creating and maintaining the charge separation between a battery’s terminals?"Answer: Chemical energy "Which of the following statements most accurately describes the behavior of a parallel RLC circuit?"Answer: The voltage waveform for each component always has the same amplitude and phase as the applied voltage "What is the equivalent value of 1 microampere in amperes?"Answer: one-millionth of an ampere "Which of the following statements best explains the concept of magnetic hysteresis?"Answer: Hysteresis is most apparent when the current through the coil of an electromagnet changes frequently Which one of the following phrases best describes residual magnetism?Answer: Magnetism that remains in the core of an electromagnet after the current through the coil is turned off If a transformer has a primary voltage of 120 V (rms) and a secondary voltage of 25 V (rms), with a secondary current of 1 A (rms), what is the value of the primary current?Answer: 208 mA Which of the following statements best characterizes the behavior of a purely inductive circuit?Answer: Inductive reactance provides the only opposition to current flow The knee voltage of a diode is approximately equal to theAnswer: Barrier potential A zener regulator has an input voltage from 15 to 20 V and a load current from 5 to 20 mA. If the zener voltage is 6.8 V, what value should the series resistor have?Answer: 410 Ohm A zener regulator has an input voltage from 15 to 20 V and a load current from 5 to 20 mA. If the zener voltage is 6.8 V, what value should the series resistor have?Answer: 410 Ohm A zener regulator has an input voltage from 15 to 20 V and a load current from 5 to 20 mA. If the zener voltage is 6.8 V, what value should the series resistor have?Answer: 410 Ohm The rms value of a sine waveform is:Answer: equal to 0.707 times the peak amplitude Which one of the following is a direct statement of Ohm's law?Answer: The voltage drop across a resistance is proportional to the value of resistance and the amount of current flowing through it A high-pass filter:Answer: passes higher-frequency signals and reduces lower-frequency signals Which one of the following statements is true for the voltages in a series RC circuit?Answer: The total voltage is less than the sum of the voltages across the resistance and capacitance A battery is a device composed of one or more:Answer: chemical cells Doubling the operating voltage of a purely capacitive circuit:Answer: has no effect on the capacitive reactance How much current flows through a 0.02-H choke that is operating from a 12-V ac, 100-Hz source?Answer: 0.955 A The transistor has a collector current of 10 mA and a base current of 40 mA. What is the current gain of the transistor?Answer: 250 μA What is the phase shift between total current and voltage in the circuit of a 100 ohm resistor connected in parallel with a capacitor that has a reactance of 100 ohmAnswer: 45 degree Molecule isAnswer: The smallest particle of a substance that retains the properties of that substance What form of energy is used for creating static electricity?Answer: Light energy Suppose the zener diode has a breakdown voltage of 10 V and zener resistance of 8.5 W, what is the additional voltage when the current is 20 mA?Answer: 0.17 V A transistor has a current gain of 125 and a base current of 30 µA. What is the collector current?Answer: 3.75 mA A dielectric material is:Answer: a good insulator A certain electromagnet has 1000 turns of wire. How much current must flow through the coil in order to generate an mmf of 100 ampere-turns?Answer: 1000 A