PST Wapda Junior Engineer 2018 Past Paper with Answers

Practice the PST Wapda Junior Engineer 2018 past paper with 91 solved MCQs, answers and topic coverage.

91 solved MCQs across 1 approved paper

A two-terminal variable resistor is known as aAnswer: Rheostat 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 one of three series resistors is removed from a circuit and the circuit is reconnected, the currentAnswer: increases All the voltage drops and the source voltage added together in a series circuit is equal toAnswer: Zero If a 24 V and a 6 V battery are series opposing, the total voltage isAnswer: 18 V When the current through the coil of an electromagnet reverses, theAnswer: Direction of the magnetic field reverses The unit for reluctance isAnswer: At/Wb The winding resistance of a coil can be increased byAnswer: Increasing the number of turns or using thinner wire When the current through an inductor is cut in half, the amount of energy stored in the electromagnetic fieldAnswer: Is quartered The primary winding of a power transformer should always beAnswer: Fused When the frequency of the source voltage decreases, the impedance of a parallel RC circuitAnswer: Increases Dielectric strength In case of mica can be expected to be more thanAnswer: 1500 kV/mm All of the following dielectric material are preferred for high frequency application exceptAnswer: Butyl rubber Polar dielectric are normally used forAnswer: Energy storage and capacitor applications Which of the following are polar dielectricAnswer: Water The impurity in liquid dielectric which has significant effect in reducing the breakdown strength, isAnswer: Moisture A good dielectric should have all the following properties exceptAnswer: High electrical conductivity The variety of paper used for insulation purpose isAnswer: Kraft paper Corona effect can be identified byAnswer: Hissing sound and bluish-violet glow In van de graaff generator output voltage is controlled byAnswer: Size of the upper dome A tesla coil isAnswer: A high-frequency high-voltage transformer Insulators for high voltage applications are tested forAnswer: Dielectric strength Transformer contribute to radio interference due toAnswer: Corona discharge The electrical breakdown strength of insulating material depend onAnswer: All of these Vacuum insulation is used in all of the following exceptAnswer: Power transformers Liquid are generally used as insulating material up to voltage stresses of aboutAnswer: 50 kV/cm The number 3.2 * 10^-5 A expressed using a metric prefix isAnswer: 32 μA A resistor is connected across a 50V source. What is the current in the resistor if the color code is red, orange, orange, silverAnswer: 2.17 mA Approximately how many mill amperes of current flow through a circuit with a 40V source an d6.8Kohm of resistanceAnswer: 5.88 mA