⚡ Electrical Engineering Solved MCQs with Answers

Practice 757 approved ⚡ Electrical Engineering questions with verified answers from the 🛠️ Engineering Essentials subject for Pakistan exams.

757 solved MCQs

The primary winding of a transformer has 110 V ac across it. What is the secondary voltage if the turns ratio is 8?Answer: 880 V In a certain loaded transformer, the secondary voltage is one-fourth the primary voltage. The secondary current isAnswer: Four times the primary current In a certain transformer, the input power to the primary is 120 W. If 8.5 W are lost to the winding resistance, what is the output power to the load, neglecting any other issues?Answer: 111.5 W In a series RL circuit, 12 V rms is measured across the resistor, and 14 V rms is measured across the inductor. The peak value of the source voltage isAnswer: 26.0 V The maximum output voltage of a certain low-pass filter is 15 V. The output voltage at the critical frequency isAnswer: 10.60 V In applying the superposition theorem,Answer: The sources are considered one at a time with all others replaced by their internal resistance In order to get maximum power transfer from a capacitive source, the load mustAnswer: Have an impedance that is the complex conjugate of the source impedance In a certain series resonant circuit, VC = 125 V, VL = 125 V, and VR = 40 V. The value of the source voltage isAnswer: 40 V When the current through an inductor is cut in half, the amount of energy stored in the electromagnetic fieldAnswer: Is quartered When the current through an inductor decreases, the amount of energy stored in the electromagnetic fieldAnswer: Decreases When the speed at which a conductor is moved through a magnetic field is increased, the induced voltageAnswer: Increases The induced voltage across a coil with 250 turns that is located in a magnetic field that is changing at a rate of 8 Wb/s isAnswer: 2,000 V If the cross-sectional area of a magnetic field increases, but the flux remains the same, the flux densityAnswer: Decreases A coil of wire is placed in a changing magnetic field. If the number of turns in the coil is decreased, the voltage induced across the coil willAnswer: Decrease There is 900 mA of current through a wire with 40 turns. What is the reluctance of the circuit if theflux is 400 Wb?Answer: 90,000 At/Wb The output of a certain voltage divider is 12 V with no load. When a load is connected, the output voltageAnswer: Decreases A 15 V source is connected across a 12 resistor. How much energy is used in three minutes?Answer: 0.938 Wh A 6 V battery is connected to a 300 load. Under these conditions, it is rated at 40 Ah. How long can it supply current to the load?Answer: 2,000 h What is the approximate resistance setting of a rheostat in which 650 mA of current flows with a 150 V source?Answer: 230 Ω The magnetic material used in temporary magnets is:Answer: Soft iron The main advantage of temporary magnets is that we can:Answer: Change the magnetic flux The current conduction through the solution of an electrolyte is by:Answer: Ions For the process of electrolysis, we require:Answer: DC supply A positive charged atom is sometimes called:Answer: Cation An Active element in a circuit is one which:Answer: Supplies energy Electric field inside negative charge is:Answer: Radial and in-word Electric potential is a:Answer: Scalar quantity Power factor at resonance is:Answer: Unity The capacitance of parallel plate capacitor does not depend upon:Answer: Metal of plates In order to enlarge the capacitance of parallel plate capacitor, one should initiate among the plates of sheet:Answer: Mica