Question

A student constructed a series circuit consisting of a 12.0-volt battery, a 10.0-ohm lamp, and a

resistor. The circuit does not contain a voltmeter or an ammeter. When the circuit is operating, the
total current through the circuit is 0.50 ampere.
Determine the equivalent resistance of the circuit.

Answer 1

Considering the unknown resistence as R and using the Ohm's First Law, we have:


`i= (V)/(R_(eq)) \\ 0.5= (12)/(R+10) \\ R+10=24 \\ R=14-Ohm`

The equivalent resistence is given by the resistor series with the lamp resistence.


`R_(eq)=R+10 \\ R_(eq)=14+10 \\ \boxed {R_(eq)=24-Ohm}`

If you notice any mistake in my english, please let me know, because i am not native.