## Power Grid Company of Bangladesh Ltd. – PGCB Questions

Power Grid Company of Bangladesh PGCB questions, all the previous year questions for recruitment test of Sub-assistant or Assistant Engineer post of Electrical.

#### Power Grid Company of Bangladesh Ltd. PGCB Questions Assistant Engineer (AE) 2011(BUET)

• Determine the voltage difference between a and b.

Figure

• Find the maximum power

Figure

Draw Thevenin equivalent circuit. Fin Vth and Rth.

• In the following circuit, the frequency of the motor is 50 Hz. To improve power factor from 0.6 lagging to unity what should be the value of C?

Figure

• In a balanced 3-wire Y connected system, a 3-phase load has a phase voltage of 240V, a line current of 5A at lagging power factor 0.966. Draw the phasor diagram.
• Assume the diode is silicon diode. Draw its output wave shape
• Figure
• 10V (P-P), 1 kHz sinusoidal signal is applied to OP-AMP input (inverting) & non-inverting input is grounded. Draw the output waveform.
• 750 KVA, 2300 V, ∆-connected 3-Ф alternator had open and short circuit tests. Following data’s are achieved from those tests:
short circuit test: If = 31.5 IL = rated.
Open circuit test: If = 31.5 VL = 1050 V.
DC resistance across the armature terminal was measured as 0.42 Ω. Calculate voltage regulation at 0.8 power factor lagging.
• Draw the single line diagram of a power system.
• A transmitter is transmitting data at a rate of 65Kbps. At the receiver, the error detector detects 32 errors in the received bits in 15 seconds of data transmission. Calculate the BER (bit error rate) of the communication system.
• The Population of Bangladesh is 150 million. Its GDP is TK. 21200 billion and the annual energy consumption is 642.17 x 106 GJ. Calculate Energy intensity in Bangladesh.
• If the signal at the beginning of the cable is 2mW & cable loss is -0.3dB/Km. what is the power of the signal at the receiver at a distance of 5Km?
• A TV signal (video and audio) has a bandwidth of 4.5 MHz. This signal is sampled, quantized, and binary coded to obtain a PCM signal.
(a) Determine the sampling rate if the signal is to be sampled at a rate of 20% above the Nyquist rate.
(b) If the samples are quantized into 1024 levels, determine the minimum bandwidth required to transmit the signal.
• An overhead line at a river crossing is supported form two towers at a height of 50m and 85m above water level. The horizontal distance between the towers being 450m. If the maximum tension is 3980kgf and the conductor weight 1.726kgf/m, find
(a) The minimum clearance.
(b) The clearance between the conductor & water level at a point midway between the towers.
(c) The clearance between the conductor & water level at a point 200m from the lower-level support.

Short Questions:

• Which type of circuit is used to convert square wave to triangular wave?
• What is the alternation torque angle?