A Question about Parallel Resistances

[bibo_dvd]

Hello Guys !

My question is : why in these photos the ohmmeter reads the total resistance ??

I mean why in (a) the ohmmeter can't read the 8 ohms resistance ?

and

Why in (b) the ohmmeter can't read the (2||10 ) resistance ?

Thank you Guys !

 

[UltrafastPED]

If you want the resistance of a component you often need to disconnect it from the circuit.

In this case the connections for the ohmmeter in (a) would give the same reading if you slid the contacts along the wires to a position as shown in (d).

 

[dlgoff]

Your ohm meter has a battery that supplies a current to your circuit. Here's what's happening (V_B would be you meters battery supply):

http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

 

[sophiecentaur]

If there are many paths for current to take then it will take them. The meter just measures the amount of current that it supplies from its internal source of volts and does the Sum R = V/I. It can't know which portion of the current is going through which resistor. So you need to measure each resistor separately. This will involve disconnecting one end of the other two. (You needn't disconnect both ends.)