A simple circuit is made of a power source, a rheostat and an ohmic resistor. The potential difference across the resistor is initially 5.0 +/- 0.1 V. A good lab student measures the current across the resistor to be 1.65 +/- 5 mA.
a)If the student increases the voltage across the resistor to 9.0 +/- 0.1 V, around what value should the measurement of the current across the resistor be (include uncertainties)?
b)what was the purpose of the rheostat in the circuit?
Physics - drwls, Tuesday, February 10, 2009 at 1:14am
Are you sure the 1.65 +/- 5 mA is correct? That could be any value between 6.65 mA and -3.35 mA.
Did you mean 1.65 A +/- 5 mA ?
The rheostat in the circuit allows the current in the resistor to vary with a fixed-voltage power source (like a battery).
Physics - Nina, Tuesday, February 10, 2009 at 1:30am
The problem says 1.65 (plus on top and the minus sign below it) 5 mA
I think the plus and minus is the uncertainties.
How would you be going about it doing both values....
I have no idea how to solve it and what the outcome is?