PTS Pakistan Testing Service 2019 Past Paper with Answers

Practice the PTS Pakistan Testing Service 2019 past paper with 58 solved MCQs, answers and topic coverage.

58 solved MCQs across 1 approved paper

PST Wapda Junior Engineer Past Paper 26-05-2019PST Wapda Junior Engineer · 2019

A two-terminal variable resistor is known as aAnswer: Rheostat A power supply produces a 0.6 W output with an input of 0.7 W. Its percentage of efficiency isAnswer: 85.7% A given power supply is capable of providing 6 A for 3.5 h. Its ampere-hour rating isAnswer: 21 Ah If you used 400 W of power for 30 h, you have usedAnswer: 12 kWh If you used 600 W of power for 60 h, you have usedAnswer: 36 kWh If it takes 400 ms to use 12,000 J of energy, the power isAnswer: 30 kW How many watt-hours represent 65 W used for 18 h?Answer: 1,170 Wh A half-watt is equal to how many milliwatts?Answer: 500 mW Three hundred joules of energy are consumed in 15 s. The power isAnswer: 20 W How much continuous current can be drawn from a 60 Ah battery for 14 h?Answer: 4.28 A When a fourth resistor is connected in series with three resistors, the total resistanceAnswer: Increases For a given wirewound core, an increase in current through the coilAnswer: Increases the flux density When the current through the coil of an electromagnet reverses, theAnswer: Direction of the magnetic field reverses The unit for reluctance isAnswer: At/Wb Which of the following capacitors is polarized?Answer: Electrolytic A 5 mH, a 4.3 mH, and a 0.6 mH inductor are connected in parallel. The total inductance isAnswer: Less than 0.6 mH The winding resistance of a coil can be increased byAnswer: Increasing the number of turns or using thinner wire The inductance of an iron-core coil decreases ifAnswer: The number of turns is decreased The primary winding of a power transformer should always beAnswer: Fused In a series RC circuit, 12 V(rms) is measured across the resistor and 15 V(rms) is measured across the capacitor. The rms source voltage isAnswer: 19.2 V An ac circuit consists of a resistor and a capacitor. To increase the phase angle above 45°, the following condition must exist:Answer: R < X꜀ When the frequency of the voltage applied to a series RC circuit is decreased, the impedanceAnswer: Increases A 20 kHz pulse waveform consists of pulses that are 15 s wide. The duty cycleAnswer: 30% A string of five series resistors is connected across a 6 V battery. Zero voltage is measured across all resistors except R3. The voltage across R3 isAnswer: 6 V A certain series circuit consists of a 1/8 W resistor, a 1/4 W resistor, and a 1/2 W resistor. The total resistance is 1200 . If each resistor is operating in the circuit at its maximum power dissipation, total current flow isAnswer: 27 mA When one of three series resistors is removed from a circuit and the circuit is reconnected, the currentAnswer: Increases The total power in a certain circuit is 12 W. Each of the four equal-value series resistors making up the circuit dissipatesAnswer: 3 W At the end of a 14 day period, your utility bill shows that you have used 18 kWh. What is your average daily power?Answer: 1.286 kWh A resistor is connected across a 50 V source. What is the current in the resistor if the color code is red, orange, orange, silver?Answer: 2.2 mA Approximately how many milliamperes of current flow through a circuit with a 40 V source and 6.8 k of resistance?Answer: 5.9 mA