State different types of power in ac circuits. Write the expression and units for the same. Draw the power triangle.

State different types of power in ac circuits. Write the expression and units for the same. Draw the power triangle. 
by

1 Answer

Answer :

i) Active Power (P):- The active power is defined as the average power Pavg taken by or consumed by the given circuit. 

image


 ii) Reactive Power (Q):- 

The reactive power is defined as the product of voltage and current (V, I) and sine of angle between voltage (V) and current (I ) i.e. Φ

OR

The power which flows back and froth that mean it moves in both the direction in the circuit or react upon itself, is called Reactive Power.The reactive power is measured in volt ampere reactive (kVAR).


image


iii) Apparent Power (s):- 

Apparent power is defined as the product of rms values of voltage (v) and current (I) it is given by 

image 


iv) Power Triangle: 

image

by

Related questions

Explain the terms real power, apparent power and reactive power for ac circuits and also the units used.

Description : Explain the terms real power, apparent power and reactive power for ac circuits and also the units used.

Last Answer : Real Power: It is the product of voltage, current and power factor i.e. P = V I cos j and basic unit of real power is watt. i.e. Expressed as W or kW. Apparent power: It is the product of ... X current X sinj or Reactive power = V I sin j and has no other unit but expressed in VAR or KVAR.

The instantaneous power in ac circuits can be obtained by taking product of the instantaneous values of

Description : The instantaneous power in ac circuits can be obtained by taking product of the instantaneous values of 

Last Answer : The instantaneous power in ac circuits can be obtained by taking product of the instantaneous values of current and voltage

In the following figure, (not to scale) ABC is triangle, where AB=1 unit, BC=`sqrt(3)` units and AC=2 units What is the relationship among AB,BC and C

Description : In the following figure, (not to scale) ABC is triangle, where AB=1 unit, BC=`sqrt(3)` units and AC=2 units What is the relationship among AB,BC and C

Last Answer : In the following figure, (not to scale) ABC is triangle, where AB=1 unit, BC=`sqrt(3)` units ... units What is the relationship among AB,BC and CA?

Draw a circuit diagram of R.C. series circuit. Draw impedance triangle and power triangle for same circuit.

Description : Draw a circuit diagram of R.C. series circuit. Draw impedance triangle and power triangle for same circuit. 

Last Answer : Draw a circuit diagram of R.C. series circuit. Draw impedance triangle and power triangle for same circuit. 

AC Circuits with Resistance but No Reactance

Description : AC Circuits with Resistance but No Reactance

Last Answer : AC Circuits with Resistance but No Reactance AC Circuits with Resistance but No Reactance Series resistances let two resistances R 1 and R 2 are connected in series as shows in figure and there ... voltage. Voltage V A is common to both the branch hence voltage V A is common reference.

What is the need of polarity marking in polyphase AC circuits?

Description : What is the need of polarity marking in polyphase AC circuits?

Last Answer : Need of Polarity Marking in Polyphase AC Circuits: i) Polarity marking of terminals provides reference polarity for better understanding of system, even if the polarity of ac voltage changes ... of current transformers in relay protection circuit and getting desired performance is very difficult.

Compare AC & DC track circuits on i) Length of circuit ii) Application iii) Effect of stray currents. iv) Maintenance

Description : Compare AC & DC track circuits on i) Length of circuit ii) Application iii) Effect of stray currents. iv) Maintenance

Last Answer : Ans: i) Length of circuit - a) AC track circuit is having long length upto 3 to 5 km b) DC track circuit is having short length  ii)Application -a) AC track circuit is used ... ) Maintenance - a) AC track circuit has easier and cheaper maintenance b) DC track circuit has complicated maintenance 

In AC. circuits, laminated iron is invariably used in order to?

Description : In AC. circuits, laminated iron is invariably used in order to?

Last Answer : In AC. circuits, laminated iron is invariably used in order to reduce eddy current loss.

does ohm's law apply to ac circuits?

Description : does ohm's law apply to ac circuits?

Last Answer : Yes it does, but as it is supplied with ac we will have to take impedance in account.

Which of the following statements concerning AC circuits is correct? A. The power factor of a resistive circuit is always zero. B. True power in an inductive circuit always equals apparent power. C. Inductive reactance varies directly with the frequency and the inductance. D. Total opposition to the flow of alternating current depends upon the amount of reactive power.

Description : Which of the following statements concerning AC circuits is correct? A. The power factor of a resistive circuit is always zero. B. True power in an inductive circuit always equals apparent power. ... . D. Total opposition to the flow of alternating current depends upon the amount of reactive power.

Last Answer : Answer: C

Transformers are used onboard ships with AC generators to _____________. A. change frequency B. increase power output to modulating frequency controllers C. decrease power output to modulating frequency controllers D. permit higher voltage for electric motor operation and low voltage for lighting circuits

Description : Transformers are used onboard ships with AC generators to _____________. A. change frequency B. increase power output to modulating frequency controllers C. decrease power output to modulating frequency ... D. permit higher voltage for electric motor operation and low voltage for lighting circuits

Last Answer : Answer: D

Draw neat labeled diagram of single phase AC locomotive showing its various equipments of power circuit and give function of each equipment used in power circuit.

Description : Draw neat labeled diagram of single phase AC locomotive showing its various equipments of power circuit and give function of each equipment used in power circuit.

Last Answer : Functions of equipment: 1) circuit breaker: disconnects the locomotive equipment from the supply in the event of fault in the equipment / loco. 2) On load tap changer, used to control the ... 6) Traction motor: operates as per the required operating characteristics to take on the traction load.

Karnaugh map is used for the purpose of (A) Reducing the electronic circuits used. (B) To map the given Boolean logic function. (C) To minimize the terms in a Boolean expression. (D) To maximize the terms of a given a Boolean expression.

Description : Karnaugh map is used for the purpose of (A) Reducing the electronic circuits used. (B) To map the given Boolean logic function. (C) To minimize the terms in a Boolean expression. (D) To maximize the terms of a given a Boolean expression.

Last Answer : (C) To minimize the terms in a Boolean expression.

Draw and describe power triangle. State its significance.

Description : Draw and describe power triangle. State its significance.

Last Answer :  Power Triangle:   OR   Power Triangle is a right angled triangle whose sides represent the active, reactive and apparent power. It is obtained by multiplying the circuit current I ... loss due to different load. This is very important for designing the energy efficient electrical system. 

In AC circuits, AC meters measure – (1) mean values (2) rms values (3) peak values (4) mean square values

Description : In AC circuits, AC meters measure – (1) mean values (2) rms values (3) peak values (4) mean square values

Last Answer : (2) rms values Explanation: Voltages and currents for AC circuits are generally expressed as rms (root mean square) values. For a sine wave, the relationship between the peak and the rms average is: rms value = 0.707 peak value.

AC circuits develop resistance, inductance, and capacitance. The inductive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Description : AC circuits develop resistance, inductance, and capacitance. The inductive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Last Answer : Answer: A

AC circuits possess characteristics of resistance, inductance, and capacitance. The capacitive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Description : AC circuits possess characteristics of resistance, inductance, and capacitance. The capacitive reactance of a circuit is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Last Answer : Answer: A

One of the following is a possible cause of an abrupt frequency variation in a self exited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency oscillation. A. Heating and expansion of oscillator coil B. DC and RF ac heating of resistors which cause change in values C. Heating of capacitor in the oscillatorD. Loose connections in the oscillator, amplifier, or antenna circuits.

Description : One of the following is a possible cause of an abrupt frequency variation in a self exited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency ... capacitor in the oscillator D. Loose connections in the oscillator, amplifier, or antenna circuits.

Last Answer : D. Loose connections in the oscillator, amplifier, or antenna circuits.

In AC circuits, AC meters measure?

Description : In AC circuits, AC meters measure?

Last Answer : RMS values

In AC circuits, AC meters measure (1) mean values (2) rms values (3) peak values (4) mean square values

Description : In AC circuits, AC meters measure (1) mean values (2) rms values (3) peak values (4) mean square values

Last Answer : rms values

Wagner's earth devices are used in AC bridge circuits for

Description : Wagner's earth devices are used in AC bridge circuits for (a) Eliminating the effect of earth capacitances (b) Eliminating the effect of intercomponent capacitances (c) Eliminating the effect of stray electrostatic fields (d) Shielding the bridge elements

Last Answer : Wagner's earth devices are used in AC bridge circuits for Eliminating the effect of earth capacitances

State the Thevenin’s theorem. Also write stepwise procedure for applying Thevenin’s theorem to simple circuits.

Description : State the Thevenin’s theorem. Also write stepwise procedure for applying Thevenin’s theorem to simple circuits.

Last Answer : Thevenin's Theorem: Any two terminal circuit having number of linear impedance and sources (voltage, current, dependent, independent) can be represented by a simple equivalent circuit consisting of a single voltage ... 's equivalent circuit: Step V: Determination of Load current:

Draw impedance triangle and voltage triangle for RL series circuit

Description : Draw impedance triangle and voltage triangle for RL series circuit

Last Answer : impedance triangle and voltage triangle for RL series circuit

Draw a potentiometer temp. Measuring circuits and explain its?

Description : Draw a potentiometer temp. Measuring circuits and explain its?  

Last Answer : OPERATION : The input to the instrument is a measurement of some in the processes using a sensing element ( such as thermocouple ) or a device to produce direct voltage, which is the voltage (signal) ... to zero results ( null point ) the balancing ( servo motor is be longer driven )   

Draw neat labeled diagram of AC track circuit. Also give two advantages of AC track circuit.

Description : Draw neat labeled diagram of AC track circuit. Also give two advantages of AC track circuit.

Last Answer : AC Track Circuit:  Advantages of AC Track Circuit: 1. Free from effects of stray currents. 2. Track circuit is up to a long length of track in one section length up to 3km to 5 km. 3. Cheaper in costs as compared to DC track circuit. 4. Easy to install than DC track circuit. 

Draw a neat labeled diagram to show protective system for AC traction and give the function of each relay used in it.

Description : Draw a neat labeled diagram to show protective system for AC traction and give the function of each relay used in it. 

Last Answer : Protective system for AC traction:  Function Of Each Relay: For transformer -  Inverse time over current relay- as back up protection on primary (HV side) over current ... against faults near substation  Under voltage relay - protection against faults far away from substation

If a, b, c are the sides of a non-equilateral triangle, then the expression (b + c – a) (c + a – b) (a + b – c) – abc is -Maths 9th

Description : If a, b, c are the sides of a non-equilateral triangle, then the expression (b + c – a) (c + a – b) (a + b – c) – abc is -Maths 9th

Last Answer : answer:

How do you factor this expression the area of a rectangle is 4w - 10 square units.?

Description : How do you factor this expression the area of a rectangle is 4w - 10 square units.?

Last Answer : 4w - 10 = 2*(w - 5)

The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of 'a' in SI system will be (A) W/m.k (B) W/m (C) W/m.k

Description : The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of 'a' in SI system will be (A) W/m.k (B) W/m (C) W/m.k

Last Answer : (C) W/m.k

Error rate is A. an error-detectingcode based ona summation operation performed onthebits to be checked. B. a checkbit appended to anarrayof binary digits to make thesum of all thebinary digits. C. a code in which each expressionconforms to specific rules of construction, so that if certain errors occur in an expression, the resulting expression will not conform to the rulesof constructionand thus thepresence of the errors isdetected. D. the ratioof the number ofdata units in error to the total number of dataunits E. None of the above

Description : Error rate is A. an error-detectingcode based ona summation operation performed onthebits to be checked. B. a checkbit appended to anarrayof binary digits to make thesum of all thebinary digits. C. a ... ratioof the number ofdata units in error to the total number of dataunits E. None of the above

Last Answer : the ratioof the number ofdata units in error to the total number of dataunits

Is it possible for a right angled triangle with sides 3 and 4 units long to have a hypotenuse 6 units in length?

Description : Is it possible for a right angled triangle with sides 3 and 4 units long to have a hypotenuse 6 units in length?

Last Answer : answer:I'm not quite getting you. It isn't actually a triangle when the hypotenuse has these indentations, right? The hypotenuse isn't a straight line as you describe it. If the other sides are 3 ... and 5.00001, you don't have a straight line. Unless I'm misunderstanding what you're suggesting.

ABC is an acute angled triangle. CD is the altitude through C. If AB = 8 units, CD = 6 units, find the distance -Maths 9th

Description : ABC is an acute angled triangle. CD is the altitude through C. If AB = 8 units, CD = 6 units, find the distance -Maths 9th

Last Answer : answer:

The two vertices of a triangle are (2, –1), (3, 2) and the third vertex lies on the line x + y = 5. The area of the triangle is 4 units. -Maths 9th

Description : The two vertices of a triangle are (2, –1), (3, 2) and the third vertex lies on the line x + y = 5. The area of the triangle is 4 units. -Maths 9th

Last Answer : (c) (5, 0) or (1, 4) Let the third vertex of the triangle be P(a, b). Since it lies on the line x + y = 5, a + b = 5 ...(i) Also, given area of triangle formed by the points (2, -1), (3, 2) and (a, b) = 4 ... b) - (-3a + b) = 5 + 15⇒ 4a = 20 ⇒ a = 5 ⇒ b = 0. ∴ The points are (1, 4) and (5, 0).

The perimeter of a triangle with vertices (0, 4), (0, 0) and (3, 0) is: (a) 12 units (b) 11 units (c) 5units (d) (7 + √5)units

Description : The perimeter of a triangle with vertices (0, 4), (0, 0) and (3, 0) is: (a) 12 units (b) 11 units (c) 5units (d) (7 + √5)units

Last Answer : (a) 12 units

21.The ordinary two winding transformer's primary and secondary windings always have A. different no of turns B. same size of copper wire C. a common magnetic circuit D. separate magnetic circuits

Description : 21.The ordinary two winding transformer's primary and secondary windings always have A. different no of turns B. same size of copper wire C. a common magnetic circuit D. separate magnetic circuits

Last Answer : C. A common magnetic circuit

Draw a neat labelled block diagram of AC electric locomotive. State the function of each part.

Description : Draw a neat labelled block diagram of AC electric locomotive. State the function of each part.

Last Answer : labelled diagram ofAC electric locomotive:  Function of AC electric locomotive Parts: 1) Overhead contact wire: Supply of 1-ph, 25KV, 50Hz, AC is given to overhead conductor. 2) Current collecting ... mechanical power to run the train i.e. DC series motor which is used as traction motor.

ABC is a triangle right angled at C. A line through the mid-point M of hypotenuse AB and parallel to BC intersects AC at D. Show that (i) D is the mid-point of AC (ii) MD ⊥ AC (iii) CM = MA = ½ AB -Maths 9th

Description : ABC is a triangle right angled at C. A line through the mid-point M of hypotenuse AB and parallel to BC intersects AC at D. Show that (i) D is the mid-point of AC (ii) MD ⊥ AC (iii) CM = MA = ½ AB -Maths 9th

Last Answer : Solution: (i) In ΔACB, M is the midpoint of AB and MD || BC , D is the midpoint of AC (Converse of mid point theorem) (ii) ∠ACB = ∠ADM (Corresponding angles) also, ∠ACB = 90° , ∠ADM = 90° and MD ⊥ AC (iii ... SAS congruency] AM = CM [CPCT] also, AM = ½ AB (M is midpoint of AB) Hence, CM = MA = ½ AB

In trapezium ABCD, AB|| DC and diagonals AC and BD intersect at O. If area of triangle AOD is 30cm square , find the area of triangle BOC -Maths 9th

Description : In trapezium ABCD, AB|| DC and diagonals AC and BD intersect at O. If area of triangle AOD is 30cm square , find the area of triangle BOC -Maths 9th

Last Answer : In the given figure: Area of triangle ADC = Area of triangle BCD (Triangles on the same and parallel) Now subtract the area of triangle DOC from both of them so... (Area of triangle ADC - Area of ... => Area of triangle AOD = Area of triangle BOC Hence the area of triangle BOC is 30 cm square.

ABC is an isosceles triangle in which AB=AC.AD bisects exterior angles PAC and CD parallel AB.Prove that-i)angle DAC=angle BAC ii)∆BCD is a parallelogram -Maths 9th

Description : ABC is an isosceles triangle in which AB=AC.AD bisects exterior angles PAC and CD parallel AB.Prove that-i)angle DAC=angle BAC ii)∆BCD is a parallelogram -Maths 9th

Last Answer : AB =AC(given) Angle ABC =angle ACB (angle opposite to equal sides) Angle PAC=Angle ABC +angle ACB (Exterior angle property) Angle PAC =2 angle ACB - - - - - - (1) AD BISECTS ANGLE PAC. ANGLE ... AND AC IS TRANSVERSAL BC||AD BA||CD (GIVEN ) THEREFORE ABCD IS A PARALLEGRAM. HENCE PROVED........

ABC is a triangle right-angled at C. A line through the mid-point M of hypotenuse AB parallel to BC intersects AC ad D. -Maths 9th

Description : ABC is a triangle right-angled at C. A line through the mid-point M of hypotenuse AB parallel to BC intersects AC ad D. -Maths 9th

Last Answer : Given: A △ABC , right - angled at C. A line through the mid - point M of hypotenuse AB parallel to BC intersects AC at D. To Prove: (i) D is the mid - point of AC (ii) MD | AC (iii) CM = MA = 1 / 2 ... congruence axiom] ⇒ AM = CM Also, M is the mid - point of AB [given] ⇒ CM = MA = 1 / 2 = AB.

ABC is an isosceles triangle with AB = AC and BD, CE are its two medians. Show that BD = CE. -Maths 9th

Description : ABC is an isosceles triangle with AB = AC and BD, CE are its two medians. Show that BD = CE. -Maths 9th

Last Answer : Given ΔABC is an isosceles triangle in which AB = AC and BD, CE are its two medians. To show BD = CE.

Bisectors of the angles B and C of an isosceles triangle with AB = AC intersect each other at O. -Maths 9th

Description : Bisectors of the angles B and C of an isosceles triangle with AB = AC intersect each other at O. -Maths 9th

Last Answer : Solution of this question

In trapezium ABCD, AB|| DC and diagonals AC and BD intersect at O. If area of triangle AOD is 30cm square , find the area of triangle BOC -Maths 9th

Description : In trapezium ABCD, AB|| DC and diagonals AC and BD intersect at O. If area of triangle AOD is 30cm square , find the area of triangle BOC -Maths 9th

Last Answer : In the given figure: Area of triangle ADC = Area of triangle BCD (Triangles on the same and parallel) Now subtract the area of triangle DOC from both of them so... (Area of triangle ADC - Area of ... => Area of triangle AOD = Area of triangle BOC Hence the area of triangle BOC is 30 cm square.

ABC is an isosceles triangle in which AB=AC.AD bisects exterior angles PAC and CD parallel AB.Prove that-i)angle DAC=angle BAC ii)∆BCD is a parallelogram -Maths 9th

Description : ABC is an isosceles triangle in which AB=AC.AD bisects exterior angles PAC and CD parallel AB.Prove that-i)angle DAC=angle BAC ii)∆BCD is a parallelogram -Maths 9th

Last Answer : AB =AC(given) Angle ABC =angle ACB (angle opposite to equal sides) Angle PAC=Angle ABC +angle ACB (Exterior angle property) Angle PAC =2 angle ACB - - - - - - (1) AD BISECTS ANGLE PAC. ANGLE ... AND AC IS TRANSVERSAL BC||AD BA||CD (GIVEN ) THEREFORE ABCD IS A PARALLEGRAM. HENCE PROVED........

ABC is a triangle right-angled at C. A line through the mid-point M of hypotenuse AB parallel to BC intersects AC ad D. -Maths 9th

Description : ABC is a triangle right-angled at C. A line through the mid-point M of hypotenuse AB parallel to BC intersects AC ad D. -Maths 9th

Last Answer : Given: A △ABC , right - angled at C. A line through the mid - point M of hypotenuse AB parallel to BC intersects AC at D. To Prove: (i) D is the mid - point of AC (ii) MD | AC (iii) CM = MA = 1 / 2 ... congruence axiom] ⇒ AM = CM Also, M is the mid - point of AB [given] ⇒ CM = MA = 1 / 2 = AB.

ABC is an isosceles triangle with AB = AC and BD, CE are its two medians. Show that BD = CE. -Maths 9th

Description : ABC is an isosceles triangle with AB = AC and BD, CE are its two medians. Show that BD = CE. -Maths 9th

Last Answer : Given ΔABC is an isosceles triangle in which AB = AC and BD, CE are its two medians. To show BD = CE.

Bisectors of the angles B and C of an isosceles triangle with AB = AC intersect each other at O. -Maths 9th

Description : Bisectors of the angles B and C of an isosceles triangle with AB = AC intersect each other at O. -Maths 9th

Last Answer : Solution of this question

ABC is an isosceles triangle in which altitude BE and CF are drawn to equal sides AC and AB respectively (Fig. 7.15). Show that these altitudes are equal. -Maths 9th

Description : ABC is an isosceles triangle in which altitude BE and CF are drawn to equal sides AC and AB respectively (Fig. 7.15). Show that these altitudes are equal. -Maths 9th

Last Answer : In △ABE and △ACF, we have ∠BEA=∠CFA (Each 90 0 ) ∠A=∠A (Common angle) AB=AC (Given) ∴△ABE≅△ACF (By SAS congruence criteria) ∴BF=CF [C.P.C.T]

ABC is a triangle right-angled at C. A line through the mid-point of hypotenuse AB and parallel to BC intersects AC at D. Show that -Maths 9th

Description : ABC is a triangle right-angled at C. A line through the mid-point of hypotenuse AB and parallel to BC intersects AC at D. Show that -Maths 9th

Last Answer : Solution :-