If I have a generator that rotates in open circuit, do I call it "the generator has no load" or " the generator has infinite load"?
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2\$\begingroup\$ No load. Infinite load would be a short circuit. \$\endgroup\$– tcrosleyCommented Jul 3, 2016 at 10:42
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\$\begingroup\$ why? Air has infinite resistance. \$\endgroup\$– sotiriosCommented Jul 3, 2016 at 10:43
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\$\begingroup\$ I mean, load is the resistance on the circuit, right? \$\endgroup\$– sotiriosCommented Jul 3, 2016 at 10:48
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\$\begingroup\$ Load is a current (power) drawn out of source \$\endgroup\$– Artūras JonkusCommented Jul 3, 2016 at 10:54
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\$\begingroup\$ did you mean no load and infinite resistance? \$\endgroup\$– old_timerCommented Jul 3, 2016 at 11:19
5 Answers
From an electrical perspective loading refers to what is impeding powerflow.
"weak pullup", refers to a high ohmage resistor. Likewise with generation and other such powersources a low load is one that requires low power flow & this implies higher impedance.
Loading and impedance are inverse terms.
Low load --> High resistance
High load --> Low resistance
Infinite load --> short circuit
No load --> infinite resistance
Load represent how much current (power) is drawn from source. For example, if there's no load, no current (power) is drawn, voltage is still there, it's just an open circuit which has infinite resistance. If you short it out, you effectively have zero resistance (well, something near that because wires still have some). If you turn your supply on, your drawn current (power) will be set according to Ohm's law and it's going to be very high. So, no load is the right term
You would usually use the term no load. Infinite load is not a common term, but might be understood to mean short circuit.
It makes sense when you think about the current or power being taken from the source:
- Big resistor = small current flowing = small power = small load
- Small resistor = big current flowing = big power = big load
- No resistor = no power flowing = no power = no load
Also, in the last case there is literally no load attached to the generator. There is nothing plugged in.
No load. You could also call it open circuit.
Infinite load is not a phrase that is used by professionals, and as you've noticed, it causes confusion, so there's every reason not to use it.
If a truck is loaded up then it struggles compared to its unloaded situation. Infinite load on a truck would cripple it just as infinite load on a battery would effectively short circuit it.