0
Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
150 amperes
AnswerYour transformer's primary current will be:
Is = Ip (Ns/Np) = 5 (90 000/300) = 5 x 300 = 1500 A
How many micro ohms to 1 Kilo ohm?
m (milli) ohm = 1/1000 ohm
µ (micro) ohm = 1/1000000 ohm
n (nano) ohm = 1/1000000000 ohm
p (nano) ohm = 1/1000000000000 ohm
Is it possible that a current will be zero in AC?
A: The AC line 60 hz constantly goes to zero every 8.33 milliseconds
What is the approximate lagging phase angle for the current in this circuit?
Only a guess can be made - 35 degrees?
What is the voltage range for an auto with a 12vdc nominal electrical system?
You should be getting 14 volts from the alternator.
Is a Line voltage understood to be any voltage?
The Line normally refers to the live wire in a single-phase system and the three live wire of a 3-phase system.
In a 3-phase system the line voltage is usually quoted as the nominal voltage, and that is the voltage between any two of the live wires. The voltage between one of the lines and neutral is 1/sqrt(3) times less.
Why would a 110 motor runs slowly backwards?
It depends on if the motor is an AC motor, or DC motor. DC motors only run backwards when the voltages get crossed between + and -.
How do you identify that in the system the neutral is floating or not?
do a continuity test between the neutral and the metal enclosure of the equipment containing the neutral. infinity reading [ open line ] indicates floating neutral. Steve sorensen jr
What are three requirement for connecting the transformer in paralle?
Transformer capacity (kvA) shall be identical, Both transformer impedance, secondary voltage and frequency shall be identical.
100amp breaker is 100amp on both phases or one phase?
A two pole breaker protects both L1 and L2 legs. An over current on either leg will trip the breaker.
What are limitations of z transform?
1.z transform can not aaply in continious signal.
2.z transform can not analyse analog filter
by - prakash kr
The voltage would 9V minus any drop in the battery.
State one possible risk caused by mains voltages.?
One possible risk caused by mains voltages is electric shock, which can occur if a person comes into contact with exposed wiring or faulty electrical appliances. This can lead to serious injuries, including burns, nerve damage, or even death. Additionally, electric shocks can cause secondary accidents, such as falls, if the person reacts unexpectedly. Proper insulation, grounding, and safety protocols are essential to mitigate this risk.
How can you tell which is the gate terminal on an SCR?
Since the gate needs very small amount of current for operation the small terminal is the gate.
How do you tap off of a 480 volt disconnect?
You don't. You hire a qualified electrician who doesn't need to read this page for the answer.
That said, if you are merely curious as to the methods:
"480" Volt will be 3-phase with either Delta wiring (480 phase-to-phase, NO neutral), or Wye wiring (480 phase-to-phase, and 277 phase-to-neutral).
You can use this directly, to run three phase equipment from all three phases, to run equipment at 480 from just two phases (being careful to keep loads balanced), or to run lighting circuits from the 277-to-neutral (being careful to size the neutral conductor carefully).
You can also step it down to "208", which will be 208 phase to phase and 120 phase to neutral -- "standard" line voltage.
But seriously, if you need to ask the question, you SHOULD NOT be touching 480 switchgear and wiring, for the safety of both yourself and others.
What Reduced power and response time of the motors is an early indicator?
1. Bearing problem
2. Load condition has gone worse.
3. Loss of voltage across motor terminals, loose connection.
Any one of them or all. If the motor is driven by VFD or soft starter, there could be some other reason related to them.
Can you give an SWG chart with current carrying capacity?
AWG gauge
Conductor
Diameter Inches
Conductor
Diameter mm
Ohms per 1000 ft
Ohms per km
Maximum amps for chassis wiring 裸線
Maximum amps for
power transmission
Maximum freqency for
100% skin depth for solid conductor copper
OOOO
0.46
11.684
0.049
0.16072
380
302
125 Hz
OOO
0.4096
10.40384
0.0618
0.202704
328
239
160 Hz
OO
0.3648
9.26592
0.0779
0.255512
283
190
200 Hz
0
0.3249
8.25246
0.0983
0.322424
245
150
250 Hz
1
0.2893
7.34822
0.1239
0.406392
211
119
325 Hz
2
0.2576
6.54304
0.1563
0.512664
181
94
410 Hz
3
0.2294
5.82676
0.197
0.64616
158
75
500 Hz
4
0.2043
5.18922
0.2485
0.81508
135
60
650 Hz
5
0.1819
4.62026
0.3133
1.027624
118
47
810 Hz
6
0.162
4.1148
0.3951
1.295928
101
37
1100 Hz
7
0.1443
3.66522
0.4982
1.634096
89
30
1300 Hz
8
0.1285
3.2639
0.6282
2.060496
73
24
1650 Hz
9
0.1144
2.90576
0.7921
2.598088
64
19
2050 Hz
10
0.1019
2.58826
0.9989
3.276392
55
15
2600 Hz
11
0.0907
2.30378
1.26
4.1328
47
12
3200 Hz
12
0.0808
2.05232
1.588
5.20864
41
9.3
4150 Hz
13
0.072
1.8288
2.003
6.56984
35
7.4
5300 Hz
14
0.0641
1.62814
2.525
8.282
32
5.9
6700 Hz
15
0.0571
1.45034
3.184
10.44352
28
4.7
8250 Hz
16
0.0508
1.29032
4.016
13.17248
22
3.7
11 k Hz
17
0.0453
1.15062
5.064
16.60992
19
2.9
13 k Hz
18
0.0403
1.02362
6.385
20.9428
16
2.3
17 kHz
19
0.0359
0.91186
8.051
26.40728
14
1.8
21 kHz
20
0.032
0.8128
10.15
33.292
11
1.5
27 kHz
21
0.0285
0.7239
12.8
41.984
9
1.2
33 kHz
22
0.0254
0.64516
16.14
52.9392
7
0.92
42 kHz
23
0.0226
0.57404
20.36
66.7808
4.7
0.729
53 kHz
24
0.0201
0.51054
25.67
84.1976
3.5
0.577
68 kHz
25
0.0179
0.45466
32.37
106.1736
2.7
0.457
85 kHz
26
0.0159
0.40386
40.81
133.8568
2.2
0.361
107 kH
27
0.0142
0.36068
51.47
168.8216
1.7
0.288
130 kHz
28
0.0126
0.32004
64.9
212.872
1.4
0.226
170 kHz
29
0.0113
0.28702
81.83
268.4024
1.2
0.182
210 kHz
30
0.01
0.254
103.2
338.496
0.86
0.142
270 kHz
31
0.0089
0.22606
130.1
426.728
0.7
0.113
340 kHz
32
0.008
0.2032
164.1
538.248
0.53
0.091
430 kHz
Metric 2.0
0.00787
0.200
169.39
555.61
0.51
0.088
440 kHz
33
0.0071
0.18034
206.9
678.632
0.43
0.072
540 kHz
Metric 1.8
0.00709
0.180
207.5
680.55
0.43
0.072
540 kHz
34
0.0063
0.16002
260.9
855.752
0.33
0.056
690 kHz
Metric 1.6
0.0063
0.16002
260.9
855.752
0.33
0.056
690 kHz
35
0.0056
0.14224
329
1079.12
0.27
0.044
870 kHz
Metric 1.4
.00551
.140
339
1114
0.26
0.043
900 kHz
36
0.005
0.127
414.8
1360
0.21
0.035
1100 kHz
Metric 1.25
.00492
0.125
428.2
1404
0.20
0.034
1150 kHz
37
0.0045
0.1143
523.1
1715
0.17
0.0289
1350 kHz
Metric 1.12
.00441
0.112
533.8
1750
0.163
0.0277
1400 kHz
38
0.004
0.1016
659.6
2163
0.13
0.0228
1750 kHz
Metric 1
.00394
0.1000
670.2
2198
0.126
0.0225
1750 kHz
39
0.0035
0.0889
831.8
2728
0.11
0.0175
2250 kHz
40
0.0031
0.07874
1049
3440
0.09
0.0137
2900 kHz
What is the function of earth switch in feeders?
For high-voltage systems, before any maintenance work can start, the feeder must be disconnected (switched off), isolated, and earthed. An earth switch provides a means of earthing the feeder.
The Thevenin equivalent circuit of this battery is 1.5V and 0.6 ohms in series. A more exact answer cannot be given without knowing the actual resistance of the 2 meters (I assumed infinite for the voltmeter and zero for the ammeter, as would be for ideal meters).
However I would NEVER attempt this test as you describe it, many types of batteries will explode like bombs when shorted (as they would be when an ammeter was placed across them)! The correct way to do this test safely is with just a voltmeter and an adjustable high wattage resistor.
What size breaker for a 9.4Kw 3 phase machine?
To determine the appropriate circuit breaker size for a 9.4 kW three-phase machine, you can use the formula: Breaker Size (Amps) = Power (Watts) / (Voltage × √3). Assuming a standard voltage of 400V, the calculation would be approximately 13.5 Amps. It's advisable to select a breaker rated higher than this calculated value, typically rounding up to the nearest standard size, such as a 16A or 20A breaker, to account for inrush currents and ensure safety. Always consult local electrical codes and a qualified electrician for specific requirements.
Which kind of motor used in winder?
Winders typically use synchronous or stepper motors. Synchronous motors provide precise speed control and consistent torque, making them ideal for applications requiring accurate winding tension. Stepper motors are also popular due to their ability to control position and speed with high precision, which is essential for winding processes. The choice between these motors depends on the specific requirements of the winding application.
The transformer size is calculated by using the load current that is required on the secondary side of the transformer. This secondary current is multiplied by the secondary voltage times 1.73. This total is then divided by 1000 to give you KVA. KVA = I x E x 1.73/1000.
They are blown venturi tubes.
A small volume of high pressure air is blown over the curved "wing" of the Dyson ring. This air adheres to the ring via the Coanda Effect and transfers momentum to the air in the ring, creating a high volume of low pressure air.
What is the input and output voltage range of ic7408?
A: The answer deviate from IC to ic . It is defined not as voltage but rather as unit loads. In other words there is a limit to how many inputs can be tied together along with how many units can be driven for reliable operation. So basically is a question of current sink and source for both input and output which strictly relates to reliable triggering voltage levels. If I remember i used the 8 for unit load for the input and 40 unit load for the output. These numbers are general use for design.
