# What is the meaning of RMS value?

What is the meaning of RMS value?

RMS value or Root Mean Square value is defined as the steady value of an alernating waveform. The RMS value makes it more easy to compare an alternating waveform with the steady waveform.
RMS value means root mean square value. It is 0.707 times peak value of voltage or current. The ammeter and voltmeter records this rms value. RMS value for sine wave is more than average value. RMS value is also called effective value.

RMS value of AC is given by DC which is flowing through a resistance for a given time and producing same amount of heat as produce by AC when AC is flowing through the same resistance for same time.

## Related questions

Description : Define : i) Average value ii) RMS value of an AC Wave.

Answer : i) Average value: The average value is defined as the average of all instantaneous values during one alternation . That is, the ratio of the sum of all considered instantaneous values to the ... as produced by the alternating current when flowing through the same resistance for the same time.

Description : RMS value formula

Description : Define RMS value.

Answer : RMS Value of Sinusoidal AC Waveform: The RMS value is the Root Mean Square value. It is defined as the square root of the mean value of the squares of the alternating quantity over one cycle ... power or heat as is produced by the alternating current during the same time under the same conditions.

Description : The equation of 50 Hz current sine wave having r.m.s. value of 60 A is?

Description : The r.m.s. value of pure cosine function is?

Answer : 0.707 of peak value

Description : The r.m.s. value of a sinusoidal A.C. current is equal to its value at an angle of______degrees.

Answer : The r.m.s. value of a sinusoidal A.C. current is equal to its value at an angle of 45 degrees.

Description : The r.m.s. value and mean value is the same in the case of?

Answer : The r.m.s. value and mean value is the same in the case of square wave.

Description : Define : i) Maximum Value ii) RMS Value of ac supply

Answer : i) Maximum Value :- The maximum or peak value attained by an alternating quantity during positive or negative half cycle, is called maximum value or peak value.  ii) RMS Value of ac ... as produced by the alternating current when flowing through the same resistance and for the same time.

Description : What is the RMS voltage in a series RL circuit, if the voltage across R and L is 256 V and 192 V respectively? A) 320 V B) 448 V C) 64 V D) None of these

Answer : What is the RMS voltage in a series RL circuit, if the voltage across R and L is 256 V and 192 V respectively? A) 320 V B) 448 V C) 64 V D) None of these

Description : In which of the following waveforms is RMS voltage equal to the average voltage? A) Triangle wave B) Square wave C) Sine wave D) None of these

Answer : In which of the following waveforms is RMS voltage equal to the average voltage? A) Triangle wave B) Square wave C) Sine wave D) None of these

Description : What is the maximum value of power factor?

Answer : 1 is the maximum value of power factor.

Description : What is the value of Beta in power BJT?

Answer : The beta value in power BJT is 5 to 10.

Description : Define Dielectric Strength for transformer oil. State its value for new transformer oil.

Description : Calculate the value of equivalent capacitance of the combination.

Answer : Calculate the value of equivalent capacitance of the combination

Description : The determinant of a 2 x 2 matrix is 50. If one eigen value of the matrix is 10, the other eigen value is ________.

Description : Average rectified value

Description : Instantaneous value of a sine wave voltage

Answer : Instantaneous value of a sine wave voltage

Description : Average value

Description : Define average value.

Answer : Average Value of Sinusoidal AC Waveform: The average value is defined as the arithmetical average or mean value of all the values of an alternating quantity over one cycle.  And/OR  For ... charge as is transferred by the alternating current during the same time under the same conditions.

Description : Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary

Answer : Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary

Description : True value has been 50 whereas measured value is 40 then the percentage error in the reading will be ______.  (A) 20% (B) 40% (C) 50% (D) 30%

Answer : True value has been 50 whereas measured value is 40 then the percentage error in the reading will be 20%.

Description : For a round wire, the approximate value of fusing current is given by

Answer : For a round wire, the approximate value of fusing current is given by  K√d3

Description : In a synchronous generator if the excitation increased from a low value to normal value, with a fixed load  (A) The armature current increases and the power factor decreases  (B) The armature ... but is lagging  (D) The armature current decreases and the power factor increases and is leading

Answer : In a synchronous generator if the excitation increased from a low value to normal value, with a fixed load The armature current decreases and the power factor increases and is leading

Description : In a 5 bit weighted resistor D/A converters, the resistor value corresponding to LSB is 40 kΩ, and the resistor value corresponding to MSB will be (A) 0.4 kΩ (B) 3 kΩ (C) 2.8 kΩ (D) 2.5 kΩ

Answer : In a 5 bit weighted resistor D/A converters, the resistor value corresponding to LSB is 40 kΩ, and the resistor value corresponding to MSB will be 2.5 kΩ

Description : In an AC. circuit, a low value of kVAR compared with kW indicates?

Answer : In an AC. circuit, a low value of kVAR compared with kW indicates high power factor.

Description : In the case of an unsymmetrical alternating current the average value must always be taken over?

Answer : In the case of an unsymmetrical alternating current the average value must always be taken over the whole cycle.

Answer : The peak value of a sine wave is 200 V. Its average value is 127.4 V.

Answer : The value of co-efficient of adhesion will be high when rails are cleaned with sand.

Answer : For measurement of inductance having high value, we should use Hay's bridge.

Answer : In a two value capacitor motor, the capacitor used for running purposes is paper spaced oil filled type.

Answer : The value of starting capacitor of a fractional horse power motor will be 300 uF .

Answer : The operating speed of a synchronous motor can be changed to new fixed value by changing frequency.

Answer : A synchronous machine with low value of short-circuit ratio has lower stability limit.

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 : Consider the sinusoidal voltage waveforms, v1(t) and v2(t), as shown  (i) State the frequency and amplitude for both the voltage waveforms. (ii) Calculate the rms value of v1(t) and v2(t), ... time domain. (vii) Calculate the instantaneous value of v2(t) at t = 38 ms.

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?

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.

Description : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is

Answer : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is 150/√3

Description : Write the relation between RMS value and Average value.

Answer : The ratio of RMS value to average value is called the form factor of an alternating quantity.

Description : Define RMS value and Average value of AC waveform.

Answer : 1. RMS value:- For an alternating current, the RMS value is defined as that value of steady current (DC) which produces the same heat or power as is produced by the alternating current during the ... by averaging all the instantaneous values of its wave over a period of half cycle. Iav=0.637 Imax

Description : Define following terms used in A.C. circuits : (i) Cycle (ii) Rms value (iii) Phase difference (iv) Average value

Answer : (i) Cycle:   A complete set of variation of an alternating quantity which is repeated at regular interval of time is called as a cycle. OR  Each repetition of an alternating quantity ... charge as is transferred by the alternating current during the same time under the same conditions.

Description : The rms value of the current in a wire which carries a d.c. current of 10 A and a sinusoidal alternating current of peak value 20 A is  (A) 10 A (B) 14.14 A (C) 15 A (D) 17.32 A

Answer : The rms value of the current in a wire which carries a d.c. current of 10 A and a sinusoidal alternating current of peak value 20 A is 17.32 A

Description : If the peak value of a sine wave is 30 V, the rms value is? A.19.08 V B.7.07 V C.0.707 V D.23.10 V

Answer : If the peak value of a sine wave is 30 V, the rms value is? A.19.08 V B.7.07 V C.0.707 V D.23.10 V

Description : In a series RLC circuit, the rms value of voltage across the resistor is 30 V, across the inductor is 60 V and across the capacitor is 20 V. The rms supply voltage would be (A) 110 V (B) 10 V (C) 220 V (D) 50 V

Description : RMS value of rectangular wave of period T, having a value of +V for a duration T1(

Description : Connotation is the same as _______. A) Intension B) Extension C) Value D) Meaning

Description : Denotation is the same as _______. A) Extension B) Intension C) Value D) Meaning