menu search
person

Most answered questions

Description :

Moving iron instruments can be used for measuring (1) Direct currents and voltages (2) Radio frequency currents (3) A.C currents and voltages (4) Both (a) and (c)

Answer :

moving iron instruments areused to measure A.C curents &  voltages

thumb_up_alt 0 like thumb_down_alt 0 dislike
5.8k views 19 answers
Description :

Which device use to convert DC to AC?

Answer :

Rectifier

thumb_up_alt 6 like thumb_down_alt 1 dislike
7.4k views 18 answers
Description :

Commutator is used in  (a) DC generator (b) AC generator (c) invertors (d) convertors

Answer :

Used in DC generators.

thumb_up_alt 0 like thumb_down_alt 0 dislike
214 views 11 answers
Description :

NOBEL PRIZE WINNERS

Answer :

Lithuania 1. Aaron Klug*, Chemistry, 1982 2. Czesław Miłosz*, born in then Russian Empire, now Lithuania, Literature, 1980 Luxembourg 1. Jules A. Hoffmann*, Physiology or Medicine, 2011 2. ... Ðức Thọ, born in French Indochina, Peace, 1973 (declined) Yemen 1. Tawakel Karman, Peace, 2011

thumb_up_alt 0 like thumb_down_alt 0 dislike
26 views 10 answers
Description :

Can transformer convert AC to DC?

Answer :

No, Transformer cannot convert AC to DC.

thumb_up_alt 4 like thumb_down_alt 1 dislike
3.0k views 9 answers
Description :

Oil in a transformer is used for  (1) insulation (2) insulation and cooling (3) lubrication (4) insulation, cooling and lubrication

Answer :

2. Insulation & Cooling

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.7k views 8 answers
Description :

What is the full form of IC?

Answer :

Instrument circuit

thumb_up_alt 1 like thumb_down_alt 0 dislike
4.4k views 8 answers
Description :

Do capacitors in parallel have the same voltage?

Answer :

Not same but we will get addition of both values when capacitors are connected in parallel...

thumb_up_alt 4 like thumb_down_alt 1 dislike
296 views 8 answers
Description :

Why are overhead transmission lines not insulated?

Answer :

Insulators are useful to help separate electrical conductors when they come into physical contact. Overhead Transmission Lines Are Not Insulated: The overhead transmission line is carrying extreme high voltage and ... a whole lot of thick insulation to absorb the heat produced by such high voltage.

thumb_up_alt 0 like thumb_down_alt 0 dislike
127 views 7 answers
Description :

Why a single phase motor is not a self starting motor

Answer :

The motor mechanical degree 360 degree this must covered revolving field so single phase to starting need starting winding with 90 degree to main winding

thumb_up_alt 3 like thumb_down_alt 0 dislike
200 views 7 answers
Description :

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

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.

thumb_up_alt 0 like thumb_down_alt 0 dislike
144 views 6 answers
Description :

Why is aluminium used instead of copper for overhead cables?

Answer :

Because copper reacts with atmosphere variation and it's cost High as compared to aluminium and aluminium is good property and less cost so aluminium is used

thumb_up_alt 0 like thumb_down_alt 0 dislike
125 views 6 answers
Description :

1.Determine the permeability of magnetic material by plotting its BH curve 2. Measure voltage, current and power in 1-phase circuit with resistive load. 3. Measure voltage, current and power in R-L series circuit. 4.Determine the transformation ratio (K) of 1-phase transformer. 5.Connect single phase transformer and measure input and output quantities. 6.Make Star and Delta connection in induction motor starters and measure the line and phase values.

Answer :

Practical no. 6 Aim: Make Star and Delta connection in induction motor starters and measure the line and phase values. Apparatus required:  voltmeter, ammeter, induction motor Circuit diagram ... Result: Hence we have measured the line and phase value of star and delta connection.

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.8k views 6 answers
Description :

State the working principle of transformer.

Answer :

Working principle of transformer : Transformer works on the principle of mutual electromagnetic induction. When AC voltage is applied to the primary winding it causes ac current to flow through primary ... the secondary winding. The current flows in the secondary circuit if load is connected.

thumb_up_alt 1 like thumb_down_alt 1 dislike
2.8k views 6 answers
Description :

Compare electric and magnetic circuit.

Answer :

.embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

thumb_up_alt 2 like thumb_down_alt 0 dislike
359 views 6 answers
Description :

what is lightning arrester?

Answer :

Light arrester is a protecting device which is used at substation for protecting the devices in the substation from lighting phenomenon.      

thumb_up_alt 0 like thumb_down_alt 0 dislike
5.3k views 6 answers
Description :

KVL examples

Answer :

KVL example

thumb_up_alt 0 like thumb_down_alt 0 dislike
98 views 5 answers
Description :

Why don't we burry power lines underground ?

Answer :

Because conductor used for power transmission are not insulated and if we do so it create phase to ground fault causing interruptions to supply.

thumb_up_alt 1 like thumb_down_alt 0 dislike
88 views 5 answers
Description :

Which wire can carry a higher current stranded wire or solid wire?

Answer :

From the formula R=PL/A resistance rise with the fall of surface area ,inverse proportion relation between Resistance and Area ,so stranded wire has more area that a solid wire so more area less resistance. Less resistance/less electron flow opposition,more electron flow (current)

thumb_up_alt 0 like thumb_down_alt 0 dislike
317 views 5 answers
Description :

Why should switch be connected only on the live wire and never on the neutral wire?

Answer :

Current runs from the transformer, through the protective device, through the load and back through the protective device (if on RCD).  If the protective device is only a CB the current passes ... the circuit will operate correctly but this is an unsafe practice and does not meet the standards.

thumb_up_alt 0 like thumb_down_alt 0 dislike
79 views 5 answers
Description :

Why cable outer sheath is black in color?

Answer :

There are cables with different colors, for example, red, orange, grey. PVC or HDPE, the plastics that the jacket of the cable is made of, have to be UV-stabilized. Carbon black is a common and cheapest additive for it purpose

thumb_up_alt 0 like thumb_down_alt 0 dislike
725 views 5 answers
Description :

5(4+1) ÷ 5(5) = ?

Answer :

5(4+1)÷5(5) LHS= 5×4+5×1 20+5 =25 RHS= 5×5= 25 Therefore= 25÷25=1 QED=1

thumb_up_alt 0 like thumb_down_alt 0 dislike
10.1k views 5 answers
Description :

Describe transistor as a switch with neat sketch.

Answer :

In Bipolar Transistor as a Switch the biasing of the transistor, either NPN or PNP is arranged to operate the transistor at both sides of the I-V characteristics curves. The areas ... possible and maximum current flowing through the transistor. Therefore the transistor is switched Fully-ON .

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.7k views 5 answers
Description :

Answer :

A Machine is Rotating Device ,It is Used To convert one form energy into Other Form.

thumb_up_alt 0 like thumb_down_alt 0 dislike
3.0k views 5 answers
Description :

Answer :

Ammeter is an measuring device which is used to measure electric  current in Ampere.this measuring device used for measuring   current of all  electrical components

thumb_up_alt 0 like thumb_down_alt 0 dislike
408 views 5 answers
Description :

Define transducer. Give two examples.

Answer :

Transducer - It converts one form of signal into another form. A transducer is a device that is used to convert a physical quantity into its corresponding electrical signal.  Classification - 1. Active transducer 2. Passive transducer 

thumb_up_alt 0 like thumb_down_alt 0 dislike
107 views 5 answers
Description :

Define : i) Amplitude ii) Frequency iii) Time period iv) Angular velocity related to a.c.

Answer :

i) Frequency:  It is the number of cycles completed by an alternating quantity in one second. ii) Time Period:  The time (in sec) required by an alternating quantity to complete its one cycle is known as time period. 

thumb_up_alt 0 like thumb_down_alt 0 dislike
165 views 5 answers
Description :

If a d.c. motor is disconnected from the source and armature circuit is short circuited through a suitable resistance, the process is called (a) regenerative breaking (b) rheostatic breaking (c) dynamic breaking (d) no breaking is possible

Answer :

b) rheostatic breaking Because rheostat is connected to chang the power dissipated into heat.

thumb_up_alt 0 like thumb_down_alt 0 dislike
134 views 5 answers
Description :

Which of the following device converts DC to AC?  A) Rectifier B) Boost converter C) Transformer D) Inverter

Answer :

Reflector

thumb_up_alt 0 like thumb_down_alt 0 dislike
693 views 5 answers
image
Answer :

Module-9 DC Machines 9.1 Constructional features of DC machines The lesson discusses the important construction features of DC machines. The induced voltage in a rotating coil in a ... of meter range using instrument transformers is discussed. Version 2 EE IIT, Kharagpur

thumb_up_alt 0 like thumb_down_alt 0 dislike
133 views 5 answers
Description :

How does the electricity travel?

Answer :

Electricity can only travel when there is a force pushing it. This force is called electromotive force. Take a look at  a water pump. When you on it force(EMF)will be applied to the ... its specified destination. This same process is applied to  electricity. EMF is required to start the process. 

thumb_up_alt 0 like thumb_down_alt 0 dislike
171 views 5 answers
Description :

what is current?

Answer :

Flow of free electrons

thumb_up_alt 0 like thumb_down_alt 0 dislike
3.0k views 5 answers
Description :

what is voltage?

Answer :

Voltage is an electromotive force or potential difference expressed in volts

thumb_up_alt 0 like thumb_down_alt 0 dislike
727 views 5 answers
Description :

70 Amazing facts about your brain... by Tim Brownson

Answer :

51. Speaking of tipping, you are a lot more likely to increase your gratuity to a waiter who has gently touched your arm as you were ordering. You may not have even noticed the touch, but ... of the body, that it looks like a small, powerful heater, while everything else appears almost ghostlike. 

thumb_up_alt 0 like thumb_down_alt 0 dislike
268 views 4 answers
Description :

ABBREVIATIONS

Answer :

Q, R QMG: Quarter Master General QR: Quantitative Restriction RAF: Rapid Action Force RAM: Random Access Memory RBI: Reserve Bank of India RCC: Reinforced Concrete Cement RDF: ... in 1988 by the World Meteorological Organisation (WMO) and the United Nations Environment Programme (Unep)

thumb_up_alt 0 like thumb_down_alt 0 dislike
20 views 4 answers
Description :

UNIT 2 THE ELECTROMAGNETIC SPECTRUM

Answer :

ACTIVITY: Projecting Visible Spectra Description: Two methods for projecting the visible spectrum are explained.  Objective: To study the range of colors in the visible spectrum. National ... for Classroom Investigations, The Physics Teacher, October 1991, 29(7), pp423-427.

thumb_up_alt 0 like thumb_down_alt 0 dislike
79 views 4 answers
Description :

UNIT 1 THE ATMOSPHERIC FILTER

Answer :

Assessment: Collect student sheets. Compare the answers the students have given but focus on the last question in which students must propose solutions to the atmospheric problems associated with ... telescope designs on the Internet. Use search terms such as observatory, telescopes, and astronomy

thumb_up_alt 0 like thumb_down_alt 0 dislike
13 views 4 answers
Description :

Define stress concentration. Explain any four methods to reduce it with neat sketch.

Answer :

) The Standard cross section for a flat key, which is fitted on a 50mm diameter shaft, is 16×10mm. The  key is transmitting 475 Nm torque from the shaft to the hub. The key is made of commercial steel  (Syt=Syc=230 N/mm2). Determine the length of the key, if the factor of safety is 3.

thumb_up_alt 0 like thumb_down_alt 0 dislike
227 views 4 answers
Description :

If field current is decreased in shunt dc motor, the speed of the motor (a) remains same. (b) increases. (c) decreases. (d) none of the above.

Answer :

increases

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.0k views 4 answers
Description :

Why is AC better for long distance power transmission than DC ?

Answer :

ac is more economical to transmit for long distances . wires can be made smaller by step up transformer .. since major cost are wires to transmit .. then at the end of distance step down transformer is used for commercial use.

thumb_up_alt 0 like thumb_down_alt 0 dislike
192 views 4 answers
Description :

If 1-phase voltage is 220V, why is 3-phase 440V and not 660V ?

Answer :

Phase voltage =220v /( phase to neutral) Line voltage = 380 v ( phase to phase) Phase angle difference 120° So when two phases reach vmax +ve I.e. (+220v) + (+220v) = 440v that time due ... these event happen very fast. Hence we have 440 v only in three phase motor. √3.phase voltage= 380 v.

thumb_up_alt 0 like thumb_down_alt 0 dislike
154 views 4 answers
Description :

Electric Current

Answer :

Electric current is the flow of charges. The electrons flow from higher density area of electrons to lowers density area of electrons. The terminal of battery which we called positive terminal of ... circuit is called electric current. The unit of electric current is Coulomb per Second or Ampere.

thumb_up_alt 0 like thumb_down_alt 0 dislike
146 views 4 answers
Description :

8 ÷ 2(2 +2) = ?

Answer :

By BODMAS rule 8/2(2*2) 4*4 =16

thumb_up_alt 0 like thumb_down_alt 0 dislike
157 views 4 answers
Description :

Explain construction and working principle of single phase transformer.

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.

thumb_up_alt 0 like thumb_down_alt 0 dislike
573 views 4 answers
Description :

Describe working principle of LED with diagram.

Answer :

Constructional Diagram: * Light Emitting Diode (LED) works only in forward bias condition. When Light Emitting Diode (LED) is forward biased, the free electrons from ... gallium arsenide and gallium phosphide the emitted photons have sufficient energy to produce intense visible light.

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.8k views 4 answers
Description :

Draw and explain working of universal motor. Give two applications of universal motor.

Answer :

Figure of Universal motor:   Operation of universal motor on A.C. and D.C. supply:   *A universal motor works on either DC or single phase AC supply. When the universal motor is ... , regardless of AC or DC supply, universal motor works on the same principle that DC series motor works.  

thumb_up_alt 0 like thumb_down_alt 0 dislike
292 views 4 answers
Description :

List applications of servomotor.

Answer :

Applications of Servomotor: 1) Computers 2) Robotics and toys 3) CD/DVD players 4) Textile industries 5) Instrument servos 6) Tracking and guidance system 7) Self-balancing recorders 8 ... 9) Process controllers 10) Electromechanical actuators 11) Air-craft control system 12) Programming device

thumb_up_alt 0 like thumb_down_alt 0 dislike
180 views 4 answers
Description :

Define intrinsic and extrinsic semiconductor. 

Answer :

Intrinsic – Semiconductor in pure form is called as intrinsic semiconductor. Extrinsic – Semiconductor with added impurity is called as extrinsic semiconductor.

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.6k views 4 answers
Description :

Describe the difference between direct and alternating current.

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. 

thumb_up_alt 0 like thumb_down_alt 0 dislike
5.2k views 4 answers
Description :

You can add here did you know facts.

Answer :

The estimated voltage potential between Earth's uppermost atmosphere and Earth's surface is approximately 400kV. Power transmission lines carry a range of AC voltages between 100k and 800kV, commonly around 400k-500kV.

thumb_up_alt 0 like thumb_down_alt 0 dislike
277 views 4 answers
editAsk a Question
...