How do you calculate the voltage in a diagram when only resistances are given? The question I'm looking at is:
How is V2 6? I used KCL and KVL and couldn't solve the system of equations because there was not enough info
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\$\begingroup\$ Because 3ohm||2ohm=6/5ohm. \$\endgroup\$– Ignacio Vazquez-AbramsCommented Oct 5, 2016 at 19:53
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\$\begingroup\$ Can you explain what the || means? \$\endgroup\$– lauraCommented Oct 5, 2016 at 19:53
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\$\begingroup\$ It's the operator used to indicate impedances in parallel. \$\endgroup\$– Ignacio Vazquez-AbramsCommented Oct 5, 2016 at 19:54
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\$\begingroup\$ Guess what two parallel lines means! 3 ohm in parallel with 2 ohms. \$\endgroup\$– TransistorCommented Oct 5, 2016 at 19:54
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1\$\begingroup\$ Apparently the OP failed the basic class of introduction to electricity. If such misunderstanding exists at this level, a change in stride should be strongly advised. \$\endgroup\$– Ale..chenskiCommented Oct 5, 2016 at 20:08
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1 Answer
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3||2 = (1/3+1/2)^-1 = 6/5
Voltage divider after that:
V2 = 16*(6/5 / (6/5+2)) = 6
This works because V2 is the same for the 2 and 3 ohm in parallel. Therefore you combine the two in parallel. Now there's a 2 resistor voltage divider between 6/5 ohms and 2 ohms.
If you want to do this the more basic way, after combining 3 and 2 in parallel, you would combine that with the to to get 2+6/5 ohms. 16 volts going into that would give you the current (5amps) through the series 2 ohms. 2 ohms times the current would give you the voltage on that half (10V) and 16V - that voltage would give you the voltage on the other side.
