The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of?

1 Answer

Answer :

The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of iron loss in core.

Related questions

Last Answer : If the supply frequency to the transformer is increased, the iron loss will increase.

Description : The time period of third harmonic of power supply frequency, in milliseconds, is (A) 20 (B) 3.33 (C) 6.66 (D) 60

Last Answer : The time period of third harmonic of power supply frequency, in milliseconds, is 6.66 

Description : Explain working of Weston type frequency meter.

Last Answer : Weston Type Frequency Meter: There are two fixed coils marked as A and B. Each coil divided into two equal parts and are fixed such that their magnetic axis are perpendicular to each ... leading to deflections in either direction depending on the currents there in, due to changed impedances.

Description : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be

Last Answer : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be 2.4 kOhm

Description : Draw the wiring diagram of fluorescent tube. Explain the working of choke and starter. 

Last Answer : Fluorescent lamp:- Operation:- When switch is ON current flows through the choke-filament no1- starter-filament no. 2- to neutral, At that time choke induces high voltage which is applied to ... at the time of starting. ii) Starter: To make and break the circuit to start the tube. 

Description : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.

Description : How to Do a Triangle Choke

Last Answer : How to Do a Triangle Choke In judo and jiu-jitsu, chokes are an important part of self-defense and high-level competition. One of the more flamboyant and effective chokes in the grappling arts is ... now start to master one of the most flashy and dangerous choking manuevers in all of martial arts.

Description : 14 Weird But Effective Ways to Avoid A Bad Hair Day

Last Answer : Nothing can ruin an otherwise fine morning like uncooperative hair. The more you brush, comb or style it with your fingers, the more it frizzles or stands up like you've just been electrocuted. Waste no time ... some new things for your hair. Open that jar of mayo and say goodbye to bad hair days.

Description : How to Be an Effective Leader

Last Answer : How to Be an Effective Leader Leadership is more complex than follow the leader. Effective leadership is all about taking a group to the direction of success, and to realize the goals you all agree ... these tips, you can be an effective leader in whatever task your group is expected to perform.

Description : Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is?

Last Answer : Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is approximately equal to 1.

Description : What happens to the voltage in the secondary when the frequency of the supply in the primary is decreased? A) It increases B) It decreases C) It remains the same D) Cannot say unless the actual percentage increase in the frequency is known

Last Answer : What happens to the voltage in the secondary when the frequency of the supply in the primary is decreased? A) It increases B) It decreases C) It remains the same D) Cannot say unless the actual percentage increase in the frequency is known

Description : Draw the diagram and explain the working of ferrodynamic type frequency meter. 

Last Answer : Ferrodynamic type frequency meter: (Electrical resonance type frequency meter): It consists of a fixed coil. The supply whose frequency is to be measured is connected across it. This coil ... so selected that the moving coil takes up a convenient position when frequency is of normal value. 

Description : What is need of regulated power supply?

Last Answer : A regulated power supply is used to ensure that the output remains constant even if the input changes. But sometimes main supply voltage, load, and surrounding temperature keep changing and altering the ... power supply is needed that will accept an AC input and give a constant DC output.

Description : Two 100W, 200V lamps are connected in series across a 200V supply. The total power consumed by each lamp will be in Watts

Last Answer : 4800

Description : What will happen if the primary of a transformer is connected to D.C. supply?  (A) Transformer will operate with low efficiency (B) Transformer will operate with high efficiency (C) No effect (D) Transformer may start to smoke and burn 

Last Answer : What will happen if the primary of a transformer is connected to D.C. supply?  (A) Transformer will operate with low efficiency (B) Transformer will operate with high efficiency (C) No effect (D) Transformer may start to smoke and burn 

Description : Consider a circuit with three parallel branches connected across a DC supply. What is the ratio of the branch currents I1 : I2 : I3 if the branch resistances are in the ratio of 2 : 3 : 4 respectively? A) 2 : 3 : 4 B) 6 : 4 : 3 C) 4 : 3 : 2 D) None of these

Last Answer : Consider a circuit with three parallel branches connected across a DC supply. What is the ratio of the branch currents I1 : I2 : I3 if the branch resistances are in the ratio of 2 : 3 : 4 respectively? A) 2 : 3 : 4 B) 6 : 4 : 3 C) 4 : 3 : 2 D) None of these

Description : Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is

Last Answer : Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is constant

Description : In a three-phase supply floating neutral is undesirable because it way give rise to?

Last Answer : In a three-phase supply floating neutral is undesirable because it way give rise to unequal line voltages across the load.

Description : Why does a transformer only work with an AC supply?

Last Answer : The transformer work depends on the induction as main principle ,for that AC is the right means

Description : How To Make An Emergency Supply Kit

Last Answer : How To Make An Emergency Supply Kit Accidents and natural disasters happen; they are among the unavoidable and unpleasant occurrences that happen in life. Unfortunately, we can't predict when and ... emergency supply kit properly, and you'll be able to make it through the catastrophe unscathed.

Description : Analyze the effect of supply voltage on performance of LED as regards current, Lumen output, efficacy and life. 

Last Answer : 1) Effect on Current:- In LED current depends upon supply voltage, if voltage get changes then current also change but this change in current will be control by resistors which are connected in series.  2) ...   4) Effect on Life:- If supply voltage is not stable then life of LED get reduced. 

Description : Draw the block diagram of regulated power supply, explain function of each block and draw waveforms of each stage.

Last Answer : 1. A step down transformer 2. A rectifier 3. A filter 4. A regulator Operation of Regulated Power Supply:- Step Down Transformer:- A step down transformer will ... regulator. A regulator will maintain the output constant even when changes at the input or any other changes occur.

Description : Define phase sequence of three phase supply with waveforms. What is normal phase sequence? Which 3 standard colours are used to denote the phase sequence?

Last Answer : It  is  sunnosoidal  sequence.

Description : What is the Power Supply specification for 8085AH microprocessor? A) Single +5V supply with 10% voltage margins B) Dual +5V supply with 10% voltage margins C) Single +10V supply with 5% voltage margins D) Dual +5V supply with 5% voltage margins 

Last Answer : What is the Power Supply specification for 8085AH microprocessor? A) Single +5V supply with 10% voltage margins B) Dual +5V supply with 10% voltage margins C) Single +10V supply with 5% voltage margins D) Dual +5V supply with 5% voltage margins 

Description :  An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V 

Last Answer :  An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V 

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

Last Answer : A change of 4% in the supply voltage to an induction motor will produce a change of approximately 8% in the rotor torque

Description : The supply for arc welding is : 

Last Answer : The supply for arc welding is : Low voltage, high current ac or dc voltage

Description : While keeping the excitation constant, if the steam supply of an alternator running in parallel with another identical alternator is increased, then (A) It would over-run the other alternator (B) Its rotor ... (C) Its portion of share in load will increase (D) Its power factor would be decreased.

Last Answer : While keeping the excitation constant, if the steam supply of an alternator running in parallel with another identical alternator is increased, then Its portion of share in load will increase

Last Answer : Overhead lines for power supply to tramcars are at a minimum height of 10 m.

Last Answer : If a D.C. series motor is operated on A.C. supply, it will spark excessively, have poor efficiency, have poor power factor.

Description : A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will?

Last Answer : A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will not start at all.

Last Answer : If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then the stator current will be zero.

Last Answer : The primary reason for low power factor is supply system is due to installation of induction motors.

Last Answer : For high value of diversity factor, a power station of given installed capacity will be in a position to supply more number of consumers.

Description : In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of?

Last Answer : In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of less than 15A.

Last Answer : Rectifier is use in power supply to convert Alternating current (AC) to Direct Current (DC) .

Description : State the working principle of gears and give its applications.

Last Answer : Working Principle:  Gears are mechanical elements which transmit motion by means of successively engaging teeth.  Gears are used to transmit motion from one shaft to another or between ... Agricultural equipment.  Industrial construction.  Mining equipment.  Automotive equipment.

Description : Explain the construction and working of LVDT accelerometer with the help of diagram.

Last Answer : Explanation:* The LVDT accelerometer consists of one primary and two secondary windings which are placed on either side of central code. The two ends of the core are connected with ... in the output terminal. This output voltage is directly proportional to the vibration or acceleration. 

Description : Describe the procedure for working of paging system.

Last Answer : Pager is a Simplex Communication Device. Paging Systems are communication systems that send messages to a subscriber. Message can be numeric or alphanumeric. Paging Systems are used to notify a subscriber ... message is sent by sender to his pager and the message will be displayed in the LCD.

Description : Describe the working principle of photoelectric pickup type tacho-generator.

Last Answer : Working: Working principle: The light passes through the holes available on the rotating disc with a specific interval, depends on the angular speed of disc having equidistant holes. The frequency of this light pulses ... by N=f/HS  N=speed  f=frequency  Hs=holes on the disc

Description : Explain with neat diagram the working of photo-voltaic cell. 

Last Answer : Diagram the working of photo-voltaic cell: Working:- Solar cell operates on principle of Photo-voltaic effect    Solar cell works in following steps: The solar cell is composed ... . When you connect loads such as a light bulb, electric current flows between the two electrodes.  

Description : Explain the working of Hydro power station with schematic layout. 

Last Answer : Working of Hydro- Electric Power Plant: Water stored at high level by constructing dam across river. This stored water has potential energy. This stored water is passed to run the water ... energy and Alternator is coupled to water turbine which converts mechanical energy into electrical energy. 

Description : Explain the working of pump storage plant and also state its advantages. 

Last Answer : Working of Pumped storage hydroelectric power plant :-  It consists of head water pond (reservoir) and tail water pond by constructing a dam at tail race path.  Tail water pond and ... install as well as spinning reserve capacity of TPP as it provides additional power during peak load period.

Description : Explain working of superheater and condenser. 

Last Answer : Working of Super heater:  Super heater consist of group of tubes. Tubes are heated by absorbing temperature of flue gases passed over it . Superheated steam' is meant that steam which ... condensate is reused in boiler. This type of condenser is used for high capacity thermal power plant. 

Description : Explain working of pumped storage plant.

Last Answer : Working of pumped storage hydroelectric power plant:-  It consists of head water pond (reservoir) and tail water pond by constructing a dam at tail race path. Tail water pond and head water pond ... as centrifugal pump. Raising the water from tail water pond to head water pond through penstock.

Description : Explain working of fast breeder reactor.

Last Answer : Fast Breeder Reactor (FBR):  A fast breeder reactor produces heat and at the same time converts fertile material into fissionable material. The central portion of this reactor is a stainless ... or thermal neutrons. In fact no moderator is present at all to slow down the fast neutrons. 

Description : With neat diagram, explain the working of clip-on ammeter.

Last Answer : Working of Clip on Ammeter: Clip on ammeters are used to measure the high current flowing through bus bar, cable or fuse holders, which act as primary. It consists of split core current ... then clipped over the current carrying conductor. The dial will record the current directly. 

Description : Draw and describe working of electronic energy meter.

Last Answer : working of electronic energy meter:- 1. CT reduces current to reasonable value for current scaling network. 2. Voltage & current scaling networks reduce proportionally the voltage & ... The ADC converts the square wave frequency analog output to display the energy in watthour. 

Description : Describe with working of LCR meter for measurement of inductance. 

Last Answer : working of LCR:- A LCR meter (Inductance (L), Capacitance (C), and Resistance (R) test equipment used to measure the inductance, capacitance and, resistance of a component. It works on the ... in parallel (as would be encountered in measuring a capacitor with a leaky dielectric) [Q setting ]