For 11 kV line the capacitance per km per phase will be of the order of: 0.01 Farad
Description : For 11kV line the inductance per km per phase will be of the order of: (A) 1 H (B) 0.1 H (C) 1 mH (D) 0.1 mH
Last Answer : For 11kV line the inductance per km per phase will be of the order of: 1 mH
Description : effect of inductance and capacitance on performance of transmission line.
Last Answer : Following are the effect on performance of transmission line: 1. Due to inductance (L) voltage drop in transmission line produces. 2. Capacitor (C) draws charging current ... , transmission line efficiency, voltage regulation & also power factor of transmission line gets affected.
Description : Calculate the value of equivalent capacitance of the combination.
Last Answer : Calculate the value of equivalent capacitance of the combination
Description : Explain estimation of channel capacitance of CMOS.
Last Answer : Capacitance estimation: The dynamic response i.e. switching speed of MOS system depends on capacitance associated with the MOS devices which are formed by different layers in MOS transistors ... are due to three dimensional, distributed charge voltage relations within the device structure.
Description : What is capacitance?
Last Answer : Capacitance is the capacity of element to store electric charge in it. The unit of capacitance is Farad.
Description : Energy stored in electrostatic field of capacitance formula
Last Answer : Energy stored in electrostatic field of capacitance formula
Description : Capacitance
Last Answer : Capacitance formula
Description : 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
Last Answer : A diode in which the change in reverse bias voltage varies the capacitance is called as Varactor diode
Description : Capacitance is the ability of a body to store an__________. (A) electrical charge (B) electric current (C) voltage (D) All of the above
Last Answer : Capacitance is the ability of a body to store an electrical charge
Description : What is the capacitance when a capacitor passes a current of 31.43 mA when supplied with 40 V AC with a frequency of 1000 Hz? A) 0.125 F B) 0.125 μF C) 1257.2 μF D) None of these
Last Answer : What is the capacitance when a capacitor passes a current of 31.43 mA when supplied with 40 V AC with a frequency of 1000 Hz? A) 0.125 F B) 0.125 μF C) 1257.2 μF D) None of these
Description : Which of the following can be used to measure the capacitance of a capacitor? A) Rheostat B) Schering bridge C) Wheatstone bridge D) None of these
Last Answer : Which of the following can be used to measure the capacitance of a capacitor? A) Rheostat B) Schering bridge C) Wheatstone bridge D) None of these
Description : The time constant of the capacitance circuit is defined as the time during which voltage?
Last Answer : The time constant of the capacitance circuit is defined as the time during which voltage rises to 63.2% of its final steady value.
Last Answer : Shunt capacitance is neglected while considering short transmission line.
Description : What is the reciprocal of capacitance?
Last Answer : The reciprocal of capacitance is called elastance, and its unit is the reciprocal farad, also called the daraf.
Last Answer : Yes BJT have internal capacitances.
Description : A 800 kV transmission line is having per phase line inductance of 1.1 mH/km and per phase line capacitance of 11.68 nF/km. Ignoring the length of the line, its ideal power transfer capability in MW is (A) 1204 MW (B) 1504 MW (C) 2085 MW (D) 2606 MW
Last Answer : A 800 kV transmission line is having per phase line inductance of 1.1 mH/km and per phase line capacitance of 11.68 nF/km. Ignoring the length of the line, its ideal power transfer capability in MW is 2085 MW
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 : A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of
Last Answer : A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of 0.02 P.U
Description : The inductance of single phase two wire power transmission line per km gets doubled when the (a) Distance between wires is doubled (b) Distance between the wires is increased four fold (c) ... the wires is increased as square of the original distance (d) Radius of the wire is doubled
Last Answer : The inductance of single phase two wire power transmission line per km gets doubled when the Distance between the wires is increased as square of the original distance
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 : 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
Last Answer : Reactance relay is preferred for phase fault on short transmission line.
Last Answer : Impedance relays are used for phase faults on long line.
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 : 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 voltage in 3 phase line?
Last Answer : between 430 to 440 v
Description : The number of insulator discs (each rated 11 kV) required in a suspension type insulator string of 220 kV line is
Last Answer : The number of insulator discs (each rated 11kV) required in a suspension type insulator string of 220 kV line is 16
Description : SINGLE PHASE INDUCTION MOTORS MCQ
Last Answer : 101. After the starting winding of a single phase induction motor is disconnected from supply, it continues to run only on (a) running winding (b) rotor winding (c) field winding (d) compensating winding Ans: a ... motor is usually reduced by using (a) gearing (b) belts (c) brakes (d) chains Ans: a
Description : THREE PHASE INDUCTION MOTORS MCQ
Last Answer : 101. Insertion of resistance in the stator of an induction motor (a) increases the load torque (b) decreases the starting torque (c) increases the starting torque (d) none of the above Ans: b
Description : How to Build a Static 3 Phase Converter
Last Answer : How to Build a Static 3 Phase Converter Static 3 phase converters enable offices and residents to conserve energy efficiently. In fact, electricity is available in 3 power phases, which enables ... converter and the necessary appliances that are needed in building the main and the remote appliances.
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 : State classification of Phase controlled rectifiers.
Last Answer : Classification of phase controlled rectifiers:
Description : Single phase transformer
Last Answer : Single phase Transformer Transformer
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 : List different starting methods of three phase synchronous motor. Explain any one of them.
Last Answer : Different Starting Methods of Three Phase Synchronous Motor: As synchronous motor is not self starting, different methods of starting are as follows: 1) By using an Induction (Pony) motor 2) ... . The rotor gets pulled into synchronism and starts running at constant speed as a synchronous motor.
Description : State suitable single phase motor for following applications: (i) Table fan (ii) Mixers and Grinders
Last Answer : Application Suitable Single Phase Motor Table Fan 1) Capacitor split phase motor 2) Capacitor start capacitor run motor Mixers and Grinders 1) Universal motor 2) A.C. Series motor
Description : Draw & explain operation of phase detector.
Last Answer : In phase detector, the op-Amp basically acts as a zero crossing detector. If a sine wave is applied at the i/p, we get square wave at the op-Amp o/p (at point ... to two channel of the CRO. The time duration between the pulses corresponding to voltages represent the phase between them.
Description : Explain the concept of lagging and leading phase angle by waveform.
Last Answer : i) Leading phase angle : When two ac quantities of same frequency do not attain their respective zero or peak values simultaneously, then the quantities are said to be out-of-phase quantities. The ... Similarly, in the second diagram, the voltage is said to be lagging the current by Φ.
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.
Last Answer : Advantages of three phase induction motor https://youtu.be/27OIOCKN05U
Description : Explain construction and working principle of single phase transformer.
Last Answer : A single phase transformers is an electrical device that accepts single-phase AC power and outputs single-phase AC. PRINCIPLE... The single-phase transformer works on the principle of ... and secondary windings. Thin steel laminations shall be employed to prevent power losses from the core.
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 following techniques related to energy conservation in transmission and distribution system. (i) By balancing phase currents (ii) Variable technical losses (I2R losses).
Last Answer : (i) Balancing Phase currents: Proper (healthy balanced) three phase loads always draw equal currents in all lines but single phase loads in the 3 phase 4 wire system or loads connected between two ... . 11) Minimize I2R losses. 12) Balance the load currents. 13) Regulate the system voltages.
Description : Split phase induction motor
Last Answer : Split phase induction motor : There are two windings used in split phase induction motor. It is a type of single-phase induction motor. There are two winding one is called main winding and ... motor have low starting torque it is used for small fans, blowers, centrifugal pumps, grinders etc.
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.