# The phase difference between voltage and current wave through...

The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition is that?

The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition is that both waves must have same frequency.

## Related questions

Description : The power consumed in a circuit element will be least when the phase difference between the current and voltage is?

Last Answer : The power consumed in a circuit element will be least when the phase difference between the current and voltage is 90°.

Description : What is the difference between line and phase voltage?

Last Answer : Line voltage  is  voltage  between two  phases R &Y  (415 v)  while  phase  voltage  is  the  voltage  between  one  phase and  a neutral  B &  N   (240 v).

Description : What is the difference between line and phase current?

Last Answer : The currents flows through phase lines is called line voltage and currents flows from phase to neutral line is called phase current

Description : When the phase difference between two sinusoidal quantities is 90° they are said to be ______ A) Phase right angle B) Phase quadrature C) Phase sinuright D) None of these

Last Answer : When the phase difference between two sinusoidal quantities is 90° they are said to be Phase quadrature

Last Answer : In a single phase power factor meter the phase difference between the currents in the two pressure coils is exactly 90°.

Description : The product of apparent power and cosine of the phase angle between circuit voltage and current is?

Last Answer : In parllpar reasonans RLC circuit the current is

Description : Describe the difference between direct and alternating current.

Last Answer : Direct current is the flow of electricity or charge in one direction..  Alternative current is the flow of charge that doesn't flow in one direction.

Description : What is the difference between eddy current and hysteresis loss?

Last Answer : Loss occurred by magnetising and demagnetising process is called histerisis loss and the current flowed due to the magnetic field produced by the electric field applied is called eddy current losses

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

Last Answer : Line voltage is equal to root three times of phase voltage and line and phase currents are equal in star connection

Description : A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is (A) 28.2 mm (B) 26.4 mm (C) 24.4 mm (D) 22.0 mm

Last Answer : A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is 22.0 mm

Description : what is the difference between AC and DC current ?

Last Answer : AC is generated using Alternator. DC is generated using DC generator. AC changes its direction periodically. DC do not change its direction periodically. AC have non zero frequency. DC have zero ... Power factor of AC is between 0 and 1. But power factor of DC is always 1.

Description : Velocity of current and motion of current is same or different??

Last Answer : Velocity  of  current  is  a scalar  quantity  which  may imply an AC current   while   motion  current  is  a  vector  quantity  or a  DC  current.

Description : Draw single phase full wave mid-point converter for inductive load. Draw input and output waveforms for it.

Last Answer : Circuit Diagram: Waveforms:

Description : Give the operation of single phase full wave bridge controlled converter with RL load with a neat diagram. Also draw its waveform.

Last Answer : Single phase fully control bridge converter with RL load: 1. During positive half cycle of input voltage, T1 and T2 are forward biased and during negative half cycle, T3 and T4 are forward biased. Therefore, T1-T2 ... cycle till the firing of next pair of SCRs as shown in the waveform.

Description : Explain three phase half wave controller or three phase unidirectional controller.

Last Answer : Three phase half wave controller or unidirectional controller:

Description : Explain three phase full wave controller.

Last Answer : Three phase full wave controller: Three phase full wave controller is also called as the three-phase bidirectional controller. Let the load is star connected so at each phase there are antiparallel connected SCRs. ... conduct at the same time and the third phase will be open.

Description : Photocell and solar cell difference?

Last Answer : A photo cell is a light dependent resistor which decreases it resistance high intensity of light and is used to automatically control lights etc where as a solar cell solar or light energy into electrical energy.

Description : Describe the difference between an open circuit and a short circuit.

Last Answer : Open circuit means the wire is cut meaning power will not flow and close circuit means wire is not cut and hence power will flow.Short circuit is the same as close circuit

Description : Write difference between absolute & secondary instrument.

Last Answer : Absolute Instrument Secondary Instrument 1. These give magnitude of quantity in terms physical constants of instruments 1. These give reading directly of the quantity at the time of ... Raleigh current balance. 6. Examples - ammeter, voltmeter, amperehour meter, wattmeter etc.

Description : What is the difference between an anode and a cathode?

Last Answer : The anode is positively charged electrode and the cathode is negatively charged electrode.

Description : What is the difference between a coil and an inductor?

Last Answer : Inductor is covering with insulating material is called coil.so they differentiate between coil and inductor.

Description : what is the difference between capacitor and battery ?

Last Answer : A capacitor stores power but in very small quantitys and work in D/C and A/C circuits and it needs a power source from wich it gets the power it stores and a battery also stores power but in much larger quantitys measured in Amp/Hours

Description : A single phase transformer has resistance and reactance of 0.2 pu and 0.6 pu respectively. Its pu voltage regulation at 0.8 pf lagging would he

Last Answer : A single phase transformer has resistance and reactance of 0.2 pu and 0.6 pu respectively. Its pu voltage regulation at 0.8 pf lagging would he 0.52

Description : The potential coil of a single phase dynamometer wattmeter has 4840 Ohm resistance. Voltage across the load is 220 V. With the potential coil connected on the load side, the meter indicates 100 W. Approximate percentage error due to wattmeter connection is (A) 11% (B) 9% (C) 1.1% (D) 3%

Last Answer : The potential coil of a single phase dynamometer wattmeter has 4840 Ohm resistance. Voltage across the load is 220 V. With the potential coil connected on the load side, the meter indicates 100 W. Approximate percentage error due to wattmeter connection is 11%

Description : In an alternator at lagging power factor the generated voltage per phase as compared to that at unity power factor?

Last Answer : In an alternator, at lagging power factor the generated voltage per phase as compared to that at unity power factor must be more than terminal voltage.

Description : Why the read of 3 phase voltage is 440?

Last Answer : The  read  of  a  phase  voltage  should be approximatly  240v. This  is  because  line  voltage  equals  to quberoot of  phase  voltage.

Description : Explain the principle of ON-OFF control and phase control of AC voltage controller with suitable circuit and waveforms.

Last Answer : The integral cycle control (on-off control) and phase angle control are the two types of AC voltage controller. The principle of ON-OFF control: The on-off control is also called an integral cycle ... control. In phase control, the switch is on for some period of each cycle.

Description : What is the voltage in 3 phase line?

Last Answer : between 430 to 440 v

Description : Give the circuit analysis of current source inverter with resistive load. What are the main difference between voltage source inverter and current source inverter?

Last Answer : Current source inverter (CSI): In current source inverter, the output current is independent of load. The input current of current source inverter is constant. Current source converter converts DC input current to ... are connected in parallel. In CSI diodes are connected in series.

Description : Distinguish between AC and DC.

Last Answer : Particulars Direct Current Alternating Current Definition It is the current whose magnitude and direction do not change with respect to time. It is the current whose ... system, electroplating, Battery charging, Traction. AC machines, Domestic and industrial supply.

Description : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole)  (A) has q -axis current only (B) has d -axis current only (C) has both d and q axis currents (D) cannot be divided between q and d axis currents

Last Answer : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole) has d -axis current only

Description : Explain MCB and ELCB with connection diagram supplying single phase load.

Last Answer : OR OR Explanation: * MCB provides short circuit protection. * MCB provides overload protection * ELCB provides earth fault protection. * MCB is in series with ... occurs, the ELCB cuts off the power within the time of 0.1 sec. automatically to protect the personnel.

Description : Why is a capacitor used in a single phase motor and not in three phase motor ?

Last Answer : In 1-phase induction motor capacitor work is generate the auxiliary winding current than excite the main winding to rotor starts rotate. After rotor start rotating about 75% of their speed than auxiliary ... emf to start the motor.so,in 3-phase induction motor is self start induction motor.

Description : Define Amplitude and Phase of Sinusoidal quantity.

Last Answer : Amplitudes are expressed either as instantaneous values or mostly as peak values.  Amplitude is the fluctuation or displacement of a wave from its mean value.  Phase is the position of a ... .  Phase an expression of relative displacement between or among waves having the same frequency .

Description : working principle of single phase motor

Last Answer : The Stator of single phase induction motor houses two windings  1. Main (Running) winding 2. Auxiliary (Starting ) winding Rotor of single phase induction motor is ... with starting winding or a capacitor may be permanently connected in series with Auxiliary (Starting ) winding.

Description : Why is a three phase denoted by R, Y, B ?

Last Answer : phase 1 ,R =Red colour cable terminal, phase 2 Y=Yellow colour terminal cable,Phase 3 B=Blue colour cable terminal, N =Neutral. For identification.

Description : Explain the working of a single phase capacitor start induction motor.

Last Answer : Single phase capacitor start induction motor https://youtu.be/31lvvzU5Puc

Description : State any four advantages of three phase induction motor.

Description : What is Phase sequence? Draw waveforms of 3 phase emf.

Last Answer : Phase sequence: It is the order in which the three phases reach their peak or maximum values. It is shown in below fig. the phase sequence is A-B-C (or R-Y-B). In the following waveforms, it is ... 120º, B- phase voltage attains its positive maximum value. So the phase sequence is R-Y-B.

Description : Define balanced 3 phase load.

Last Answer : Balanced 3 phase Load: Balanced three phase load is defined as star or delta connection of three equal impedances having equal real parts and equal imaginary parts. It takes same current of equal magnitude and equal phase angle.

Description : With a neat sketch explain working of 1 phase dynamometer type power factor meter.

Last Answer : Working of 1 phase dynamometer type power factor meter : The current coil is connected in series with load. Two pressure coils marked as A and B are connected across the supply terminals ... becomes stationary and the pointer shows steady deflection corresponding to the power factor of the load.

Description : State the use of:- (i) Clip-on-ammeter (ii) Phase sequence indicator

Last Answer : (i) Clip-on-ammeter: used for measurement of current in cables/lines in live conditions without disconnecting them.  (ii) Phase sequence indicator: To determine /find the phase sequence of 3 phase supply.

Description : State the meaning of creeping error in 1 phase energy meter.

Last Answer : Creeping error: It is defined as the slow and continuous rotation of the disc of the energy-meter when only pressure coil is energized with no current in the current coil (load current = 0). ... magnet on this iron wire is sufficient to prevent continues rotation of the disc on no load condition.

Description : List any two methods of reactive power measurement in 3 phase circuit.

Last Answer : Methods of reactive power measurement in 3 phase circuit: (i) Two single phase wattmeter method (ii) One single phase wattmeter method

Description : Define balanced and unbalanced load in three phase circuit.

Last Answer : Balanced Load: When all the imedances of 3 phases are equal in magnitude and of same nature then load is said to be balanced.  Unbalanced Load: When all the imedances of 3 phases are not equal in magnitude and of different nature then load is said to be unbalanced.

Description : Describe the following errors and their compensation: (i) Phase error (ii) Speed error

Last Answer : (I) Phase error   1. In the phase error the phase difference angle between ∅ & ∅ is kept by using the shading band/ring  2. If the design and location of Shading band/ring is ... of brake magnet. By changing the position of the brake magnet speed of the rotating disc can be controlled.

Description : Describe with neat diagram phase sequence indicator.

Last Answer : Phase Sequence Indicator: There are two types of phase sequence indicators: (a) Rotating type phase sequence indicator (b) Static type phase sequence indicator (a) Rotating Type Phase Sequence ... of the supply is reversed or altered, then the lamp 1 will glow brighter than the lamp 2.

Description : State any two disadvantages of one wattmeter method of measurement of 3 phase power.

Last Answer : State any two disadvantages of one wattmeter method of measurement of 3 phase power. Disadvantages of one wattmeter method:- 1. Only used for balanced load 2. It can not be used for ... connection then neutral point must be available 4. Delta connection must be opened to connect current coil.

Description : State the application of phase sequence indicator; clip on ammeter, frequency meter & P.F. meter.

Last Answer : Phase Sequence Indicator:  1. For finding correct phase sequence of supply  2. For obtaining exact instant of parallel operation of alternators.  3. For obtaining reversal of rotation ...  4. In electroplating industries   5. In various processes industries for measuring power factor

Description : Draw and explain RC phase shift Oscillator.

Last Answer : Circuit diagram of RC phase shift oscillator: WORKING: * Circuit consists of a single stage amplifier in common emitter configuration & RC phase shifting network. * R1, R2, RE provides biasing & CE ... . * The phase shift around the loop is 3600 only at one precise frequency.