Description : Most AC voltmeters are calibrated to indicate __________. A. peak-to-peak voltage B. root-mean-square voltage C. average voltage D. peak voltage only
Last Answer : Answer: B
Description : AC voltmeters are generally calibrated to read the ________. A. instantaneous voltage B. average voltage C. RMS voltage D. peak voltage
Last Answer : Answer: C
Description : Why ammeters have to be arranged in class and voltmeters in parallel circuit ?
Last Answer : Ammeter must be added to the class because it measures the flow. When added in parallel, the flow will be divided into two parts. As a result, the exact value of the flow cannot be ... because adding voltage will change the voltage difference. But in parallel the voltage difference does not change.
Description : When voltage and current developed in an AC circuit reach their peak values at the same time, the power factor is _____________. A. lagging B. leading C. maximum D. minimum
Description : Average power dissipated in resistor if sinusoidal p.d of peak value 25 V is connected across a 20 Ω resistor is A. 15.6 W B. 15 W C. 16 W D. 17 W
Last Answer : 15.6 W
Description : Most AC voltmeters have an rms scale which is valid only if the input signal being measured is a __ signal.
Last Answer : sinusoidal
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.
Description : In AC circuits, AC meters measure (1) mean values (2) rms values (3) peak values (4) mean square values
Last Answer : rms values
Description : When the voltage and the current developed in an AC circuit reach their peak values at the same time, the power factor is considered to be _____________. A. lagging B. leading C. unity D. infinity
Description : In a two -channel oscilloscope operating in x -y mode, two in -phase 50 Hz sinusoidal waveforms of equal amplitude are fed to the two channels. What will be the resultant pattern on the screen ? (a) An ellipse (b) A parabola (c) Straight line inclined at 45° with respect to x-axis (d) A circle
Last Answer : In a two -channel oscilloscope operating in x -y mode, two in -phase 50 Hz sinusoidal waveforms of equal amplitude are fed to the two channels. What will be the resultant pattern on the screen ? (a) An ellipse (b) A parabola (c) Straight line inclined at 45° with respect to x-axis (d) A circle
Description : If 450 volts AC were measured across the load as shown in the illustration it would indicate a/an _______________. EL-0083 A. open winding between 'H1' and 'X1' B. properly operating circuit C. open winding between 'X1' and 'X4' D. ground on one side of 'Ep'
Description : External noise fields are measured in terms of _______. A. rms values B. dc values C. average values D. peak values
Last Answer : D. peak values
Description : How the ammeter’s effect on the circuit being measured is kept to a minimum?
Last Answer : The resistance of the ammeter must be much smaller than the circuit load.
Description : In the flow of one cycle of single phase AC current past any given point in a circuit, the maximum current peak occurs _____________. A. one time B. two times C. three times D. four times
Description : Draw sinusoidal waveform of 3 phase emf and indicate the phase sequence.
Last Answer : Phase sequence is R-Y-B.
Description : The ________ is a function of three values: average data rate, peak data rate, and maximum burst size.
Last Answer : Effective bandwidth
Description : What does the Voltmeter in AC mode show? Is it RMS value or peak value?
Last Answer : Multimeter in AC mode shows RMS value of the voltage or current. Also when it is DC mode it will show the RMS value only.
Description : Alternating current measured in a transmission line will be a) Peak value b) Average value c) RMS value d) Zero
Last Answer : c) RMS value
Description : Which of the following procedures should be used to determine the load of a threephase, delta wound, AC generator? A. Multiply the amperage in one phase by three. B. Divide the total amperage in all ... square root of three. D. Divide the total amperage in all phases by the square root of three.
Description : External shunts are sometimes used with ammeters to _______. A. increase meter sensitivity B. permit shunts with larger resistances to be utilized C. prevent damage to the meter movement from heat generated by the shunt D. enable the construction of a compact meter with a virtually unlimited range
Description : In our houses we get 220 V AC. The value 220 represents (a) constant voltage (b) effective voltage (c) average voltage (d) peak voltage
Last Answer : Ans:(b)
Description : Describe the operation of inductor with sinusoidal AC voltage as input. Draw waveform for voltage across and current through the inductor. Draw its phasor representation.
Last Answer : An alternating voltage is applied to a purely inductive coil, a back e.m.f. is produced due to self-inductance of the coil. The back e.m.f. at every step, opposes the rise of fall of current through the coil ... drop, the applied voltage has to overcome this self induced e.m.f. only.
Description : Explain how sinusoidal AC voltage is generated by using simple one loop generator.
Last Answer : An electric current produced by means of electrical machine is known as generator which converts mechanical energy into electrical energy. When conductor cuts the magnetic flux, emf induced in it. (Faraday' ... upon position of armature. The nature of emf is alternating as shown by the waveform.
Description : An ac voltmeter using full -wave rectification and having a sinusoidal input has an ac sensitivity equal to (1) 1.414 times dc sensitivity (2) dc sensitivity (3) 0.9 times dc sensitivity (4) 0.707 times dc sensitivity
Last Answer : An ac voltmeter using full -wave rectification and having a sinusoidal input has an ac sensitivity equal to 0.9 times dc sensitivity
Description : Explain the principle of ON-OFF control and phase control of AC voltage controller with suitable circuit and waveforms.
Last Answer : The integral cycle control (on-off control) and phase angle control are the two types of AC voltage controller. The principle of ON-OFF control: The on-off control is also called an integral cycle ... control. In phase control, the switch is on for some period of each cycle.
Description : Indicate the false statement A. The noise generated in a resistance or the resistive component of any impedance is random. B. Random noise power is proportional to the bandwidth over which is measured ... exist D. All formula referring to random noise are applicable only to the value of such noise.
Last Answer : C. A random voltage across the resistor does not exist
Description : Q-7 during welding process, why sinusoidal wave form is converted in to the square wave form?
Last Answer : In sinusoidal wave, we get maximum energy at one point only. So for the more amount of maximum energy we can get by converting the sinusoidal wave form in to the square wave form, and more penetration and deposition rate is achieved due to maximum energy.
Description : The current drawn by the line due to corona losses is (a) non-sinusoidal (b) sinusoidal (c) triangular (d) square
Last Answer : (a) non-sinusoidal
Description : The ratio of the effective value of the counter EMF in volts, to the effective value of the current in amperes is called _____________. A. impedance factor B. capacitive reactance C. inductive reactance D. root mean square
Description : What is root mean square value (R.M.S)?
Last Answer : The R.M.S value is also known as effective value or virtual value. The instantaneous value of both the directions will all be squared up and will be added together. Then divide to get the average with the number of ... = 1/√2 = 0.707. ∴ R.M.S value or effective value = 0.707 * Emax or Imax
Description : The voltage at any point in an ac circuit will be a) Peak voltage b) RMS voltage c) Average voltage d) Source voltage
Last Answer : b) RMS voltage
Description : Current flowing in only one direction is called ___________. A. alternating current B. omnidirectional current C. direct current D. sinusoidal current
Description : Which of the wave shapes shown in the illustration is termed a sinusoidal wave? EL-0088 A. A B. B C. C D. D
Description : If the electricity represented by the wave form in 'B' were applied to the left side of the illustrated circuit, the output on the right side would be ____________. EL-0064 A. direct current with the ... lower lead D. clipped to a value equal to the square root of 3 times the input voltage value
Description : If the mean stress value for a sinusoidal stress function is zero, then this type of stress falls in which category? a) Fluctuating Stresses b) Alternating Stresses c) Repeated Stresses d) Reversed Stresses
Last Answer : d) Reversed Stresses
Description : The electrical diagram shown in the illustration shows _____________. EL-0021 A. 'R1', 'R2', and 'R3' are connected is series B. 'R1', 'R2', and 'R3' are connected in parallel C. the voltages measured across ... if 'R1', 'R2' and 'R3' have different values D. the total resistance equals R1 + R2 + R3
Description : The concrete work for the following part of the building of specified thickness is measured in square metres (A) Root slabs (B) Floors (C) Wall panels (D) All the above
Last Answer : (D) All the above
Description : Why Is Flow Measured In Square Root?
Last Answer : Flow varies directly as the square root of different pressure F = K square root of ΔP. Since this flow varies as the square root of differential pressure the pen does not directly indicate flow. The flow can be determined by taking the square root of the pen. Say the pen reads 50% of chart.
Description : Tell Me How Is Flow Measured In Square Root?
Last Answer : Flow varies directly as the square root of pressure. Thus, F=K of square root of applied pressure. Since this flow varies as the square root of differential pressure. The pressure pen does not directly ... reads 50% of the chart. So, flow can be calculated using the pen measure in the chart.
Description : How Is Flow Measured In Square Root?
Description : Why flow is measured in square root?
Last Answer : Flow varies directly as the square root of different pressure F = K square root of D/P. Since this flow varies as the square root of differential pressure the pen does not directly indicate flow. The flow can be determined by taking the square root of the pen. Say the pen reads 50% of chart.
Description : Which one of the following statements about the mass spectrum of CH3Br is correct? a. the last two peaks are of equal size and occur at m/z values of 94 and 96 b. the last two peaks have abundances in the ... m/z value of 95 d. there is just one peak for the molecular ion with an m/z value of 44
Last Answer : a. the last two peaks are of equal size and occur at m/z values of 94 and 96
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
Last 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 : The RPM of an AC generator can be measured with a/an _____________. A. ammeter B. voltmeter C. vibrating reed meter D. synchroscope
Description : When the current in a power transmission line is increased, the power loss _____________. A. increases as the square of the current B. decreases as the square root of the current C. remains the same, as it is independent of current flow D. increases in direct proportion as the current
Last Answer : Answer: A
Description : Highest point on AC graph is known as A. peak value B. amplitude C. frequency D. wave front
Last Answer : peak value
Description : What are the minimum recommended PI values for AC and DC rotating machines?
Last Answer : Following minimum recommended PI values criteria is to be followed. a. 1.5 for class – A insulation. b. 2.0 for class – B insulation. c. 2.5 for class – F insulation.
Description : What are Vault Meters and Ammeters ?
Last Answer : : Ammeter is used to measure current flow and Vault meter is used to measure voltage. These two measuring instruments are usually in one place and the two are often called multimeters. A multimeter ... DC voltage and current. Today's multimeters can measure many things, not just voltage and current.
Description : How many types of ammeters ?
Last Answer : There are two types of ammeters. Namely digital ammeter , analog ammeter.
Description : X, Y and Z are ammeters and Y reads 0.5 A. (i) What are the readings in ammeters X and Z ? (ii) What is the total resistance of the circuit ?
Last Answer : X, Y and Z are ammeters and Y reads 0.5 A. (i) What are the readings in ammeters X and Z ? (ii) What is the total resistance of the circuit ?