Ohm's Law

[Anonymous No.679909]

What happens when we have a 10V power supply which can supply 100mA current max and we put a 50ohm resistor across it?

According to Ohm's Law 200mA should appear on the resistor but the supply can only give 100mA. What happens then?

[Anonymous No.679910]

supply sags down to 5v

[StuPedasso No.679914]

>>679910
or power supply goes pfffft and voltage drops to zero

[Anonymous No.679915]

>>679910
I thought it will be explode or something.
But then why won't the voltage jump up to 20V if i put a 200 ohm resistor across it?

[Anonymous No.679920]

>>679915
You should really read up on electronics. A power supply cant jump up to 20 volts.
The power supply will try and 'generate' 200 mAmps and some components will probably explode and you will burn out your power supply.

[Anonymous No.679923]

>>679909
if it says that it can only give out 100mAmps then you shouldnt put resistance to the circuit that would generate more than 100mAmps

[Anonymous No.679928]

>>679909
voltage drop
damage power supply
or fuse goes off if there is any

[Anonymous No.679929]

Let's say i put a 1 inch AWG 18 copper wire across the terminals of a 9V battery.
That is about 0.00054 ohm of resistance in the wire.
Is that battery generates 16667 amps now? (9/0.00054=16667)
Is that battery generates

[Anonymous No.679935]

>>679929
yeah you could just say it has no resistance at all so its practically short circuiting and the battery overheats and is damaged until it breaks

[Anonymous No.679938]

>>679909
if it says that it can only give out 100mAmps then you shouldnt put resistance to the circuit that would generate more than 100mAmps, because the PSU's components are not designed for more than theyre intended for and will break if exposed to wrong voltages/currents

i guess people who dont know these things havent got a degree in electronics

[Anonymous No.680101]

>>679909
The little overcurrent LED comes on. The power supply puts out 100 mA and tat ends up being 5 volts.

That's my power supply. Your's might just put out a little cloud of smoke and quit.

[Anonymous No.680112]

>>679929
No
http://en.wikipedia.org/wiki/Internal_resistance

[Anonymous No.680925]

>>679909
>According to Ohm's Law 200mA should appear on the resistor but the supply can only give 100mA. What happens then?
The fact that your 10V supply has a current rating means it's not an ideal voltage supply. No real voltage supply is.
Exceed 100mA and god knows what happens. Maybe it sags. maybe it overheats and melts. maybe it shuts off. Who knows.

[Anonymous No.680926]

>>679915
Because it's a 10V supply.
The 100mA is a maximum rating. It doesn't mean it puts out 100mA. It's a voltage supply, not a current supply. And yes, current supplies exist-- they hold the current steady and voltage is 'whatever' within a specified rated range.

[Anonymous No.681052]

>>679929
V=IR, you asshole, its not that fucking hard
if R=0, I=infinity
what happens when I=infinity asshole?
congrats, you just instructed this fucker on how to make a bomb

[Anonymous No.681054]

>>681052
>asshole fucking asshole fucker
Calm down, mr. Homosex. No need to be so upset.

[Anonymous No.681083]

>>679909
>According to Ohm's Law

Eh, we already know from the description of the power supply that it's not ideal ohmic (Which should be obvious - nothing real is ideal)

The only way to tell what will actually happen is to get a circuit diagram of the internals of the powersupply and see how it works - you'll find Ohm's Law probably comes a lot closer to true when you include all the components of the PS.

[Anonymous No.681134]

>>679909
1. Your PSU will reduce the voltage to prevent it from going over the rated amps
2. The fuse will blow
3. one of the PSU parts will blow
Pick one.

[Anonymous No.681142]

>>679909
If it is well designed (i.e. with current limiting) the voltage will drop to 5V (V=I*R=50*0.1). If it is badly designed it can range from poof to BANG

[Anonymous No.681146]

>>681142
There are all kinds of overload protections. For example, an IC regulator rated for 100mA output might have a constant current limit at 200mA (with loose tolerances) and an overheating protection against excessive power dissipation.
Purely protective current limiters are often quite inaccurate. Sometimes they also use foldback limiting.