# Recent questions tagged voltage

Is the power line voltage available in our homes a dc or an ac voltage?

Voltage ratio

Voltage divider rule

Voltage formula

Self induced voltage across an inductance

Kirchhoff's voltage law

Instantaneous value of a sine wave voltage

Why inductor current lags inductor voltage ?

Explain how sinusoidal AC voltage is generated by using simple one loop generator.

Explain lagging quantity and leading quantity, explain this concept with voltage and current waveform

Draw circuit diagram of voltage divider biasing list two advantages of voltage divider biasing of BJT.

Define pinch off voltage and drain resistance of FET.

Define Depletion region and Barrier voltage of PN junction.

State the concept of internal voltage drop.

Define : (i) Dielectric strength (ii) Breakdown voltage

What is internal voltage drop and terminal voltage?

Define: 1) voltage ratio, 2) current ratio, 3) transformation ratio of transformer.

For a balanced three phase star connected load for which line voltage is 230V and per phase resistance and reactance is 6 Ohm and 8 Ohm respectively. Calculate: 1) phase voltage 2) line current 3) power factor 4) total power absorbed

Draw the Delta connected three phase system showing all the voltages and currents. Write the power equation.

Write the relation between phase and line current, phase and line voltage for Star connection.

What is line voltage and phase voltage? Draw balanced three phase star connected system. Show all the voltages and currents.

Draw the waveform of three phase AC supply voltage.

An independent voltage source in series with an impedance ZS=R+jXS delivers a maximum average power to a load impedance ZL when A) ZL = R B) ZL = jXS C) ZL = R-jXS D) ZL = R+jXS

An SSB transmitter produces a peak-to-peak voltage of 200 V across a 100 Ω antenna load. What is the Peak Envelope Power? A) 49.98 W B) 79.98 W C) 99.96 W D) 199.93 W

The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply frequency of A) 10 kHz B) 10 Hz C) 5 kHz D) 5 Hz

A zener voltage regulator has load requirements of 12 V and 2 A. The zener diode minimum current requirement is 0.2 A. The minimum voltage at input is 24 V. What is the required value of series resistance with source? A) 5.45 Ω B) 6 Ω C) 7.2 Ω D) 6.38 Ω

A diode in which the change in reverse bias voltage varies the capacitance is called as A) Varactor diode B) Switching diode C) Tunnel diode D) Zener-diode

Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary

Two transformers A and B having equal outputs and voltage ratios but unequal percentage impedances of 4 and 2 are operating in parallel. The transformer A will be overloaded by

A change of 4% in the supply voltage to an induction motor will produce a change of approximately

The voltage of transmission can be regulated by  (A) Use of tap changing transformers (B) Switching in shunt capacitors at the receiving end during heavy loads (C) Use of capacitors to neutralize the effect of series reactance (D) Any of the above methods

The permissible voltage variation in transmission and distribution system is:  (A) ± 0.1% (B) ± 1% (C) ±10% (D) ± 25%

Step-down transformer converts high voltage and low current into:  (A) How voltage and high current (B) High voltage and low current (C) Low voltage and high current (D) None of the above

The kVA rating of Three-phase transformer with Voltage = 200V and Current = 100A will be :  (A) 34.64 kVA (B) 75 kVA (C) 20 kVA (D) None of the above

Which of the following is the least expensive protection for over current in low voltage system?  (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker

If 3000 kW power is to be transmitted over a distance of 30 km, the desirable transmission voltage will be.  (A) 11 kV (B) 33 kV (C) 66 kV (D) 132 kV

The voltage gains of the amplifier with and without feedback are 20 and 100 respectively. The percentage of negative feedback would be

An amplifier has a voltage gain of 120. To reduce distortion, 10% negative feedback is employed. The gain of the amplifier with feedback is  (1) 141 (2) 92.3 (3) 9.23 (4) 1.41

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque  (1) Decreases (2) Increases (3) Remains constant (4) None of the above

The voltage gain of a common -source JFET amplifier depends up on its  (1) Input impedance (2) Amplification factor (3) Dynamic drain resistance (4) Drain load resistance

A transformer has negative voltage regulation when its load power factor is   (1) Zero (2) Unity (3) Leading (4) Lagging

A dc chopper is fed from a constant voltage mains the duty ratio of chopper is progressively increased while the chopper feeds an RL load. The per unit current ripple would  (1) increase progressively  (2) decrease progressively  (3) decrease to a minimum value at α = 0.5 and then increase  (4) increase to a maximum value at α = 0.5 and then decrease

A voltage source inverter will have better performance if its  (1) load inductance is small and source inductance is large.  (2) both load and source inductance are small.  (3) both load and source inductances are large.  (4) load inductance is large and source inductance is small.

A 3-phase voltage source inverter operates in 180° conduction mode with a star connected resistive load. If input dc voltage is 100 V, then the peak to peak output line voltage is :

A current controlled voltage source is equivalent to :  (A) series voltage feed -back amplifier (B) shunt current feed -back amplifier (C) shunt voltage feed -back amplifier (D) series current feed -back amplifier

Identify the increasing order of voltage regulation of the following dc generators a same load :  (A) differential compound, shunt and under compound  (B) shunt, differential compound and under compound  (C) under compound, shunt and differential compound  (D) shunt, under compound and differential compound