Question

which one is not used in verifying ohms law​

Answer 1

Answer:

I = V/R IS USED FOR VERIFICATION OF OHMS LAW

Answer 2

Explanation:

Why is a rheostat used in Ohm's law circuit?

Ohm’s law circuit states about the proportionality between current and voltage in an electrical circuit, i.e., the rate of increase or decrease of current through a conductor will be same as the rate of increase or decrease of voltage supplied. Hence in order to prove it experimentally you need to input at least three different voltages and measure three different output currents through ammeter and then finally to show that V:I for all the three cases are constant, hence V and I are in proportionality. If you have the availability of three different voltage sources of different values, you may use them connecting one after another. But that seems to be a longer duration and tedious task.

By placing a rheostat (resistance of which can be varied manually as per your choice) in series with a battery or voltage source you get the option to get the fixed output voltage dropped by and large. The resistance consumes some portion of the current output from the battery as Ir and thus the voltage reached at the terminal of your test conductor is lowered. By using rheostat we can lower the voltage output of the original voltage source....Rheostat is used to provide variable resistance....

We know that V= IR, one of the derived formulae of Ohm's law. To plot a graph voltage Vs current or current Vs resistance or just to observe voltage and current values, we use these procedures:

We provide variable voltage across the rheostat and observe current.

We fix voltage and vary the resistance of rheostat and observe current.

We vary voltage and resistance of rheostat and observe current.

For case 2 and 3, resistance variation is needed and for that we use rheostat.