Electronics - Ohm's Law - Discussion

1. The resistance of a conductor is constant under constant temperature and pressure
2. The applied voltage is directly proportional to the current flowing through the conductor.

Hence the resistance value remains constant R = V/I.

It is useful to improve knowldege.

The resistance R is dependent neither on the voltage V nor on the current I. So R will remain constant.

V=IR.

Does are value remain constant always?

According to Ohms law,

V=IR and R=V/I.
If V doubles and it become 2V and I doubles and it become 2I.

Therefore R = 2V/2I = V/I (R values not change).

Once fix the resistor if then the applied current&voltage is varied randomly ,the resistance not changed.
how ever ,
we know that ohm's law
V=IR;
GIVEN THAT V=2V;
I=2I;
WE SUBSTITUTE THE OHMS LAW IN ABOVE GIVEN EQATIONS
R=2V/2I
R=V/I,
SO THE RESISTANCE VALUE IS NOT CHANGED BY VARIENG THE CURRENT AND VOLTAGE.

Pay attention to the words that is being used in the problem.
ACROSS means = parallel to the resistor.
And THROUGH means = series to the resistor.

Since,
Voltage at parallel is the same.
Current in series is the same.
We can say that Vb=2volts & Ib=2amperes in the Second Equation.

Therefore.
Using the ohms law : I = V/R.

Equation 1 : Ra = 1Va/1Ia is 1ohm.
Equation 2 : Rb = 2Vb/2Ib is 1ohm.


Conclusion.

Rb=Ra=1ohm therefore The value of the resistor remains the same and did not change.

Voltage and current are proportional to each other and are is a constant:.
V=IR.
(2V) = (2I)R.
V=IR.

Thanks eleczee.

On changing I proportional voltage, the current also change by same extent and we know that R is directly proportional to V and inversly proportional to I hence answer is B.