Question

For an Ohmic conductor, tripling the voltage without changing the resistance will cause the current to A. decrease by a factor of 3. B. increase by a factor of 3. C. increase by a factor of 9. D. decrease by a factor of 9.

Answer 1

Answer:

B. increase by a factor of 3.

Step-by-step explanation:

According to ohms law:

V ∝ R

Vo = IoR

R = Vo/Io ... (1)

Vo is the initial potential difference/voltage

Io is the initial current across the resistor

R is the resistance

If for an Ohmic conductor, we triple the voltage without changing the resistance:

New voltage V1 = 3Vo

New voltage V1 = I1R (resistance doesn't change)

I1 is the current after the voltage has tripled

3Vo = I1R

R = 3Vo/I1... (2)

Equating both resistances in 1 and 2 since resistance doesn't change we have:

Vo/Io = 3Vo/I1

1/Io = 3/I1

I1/Io = 3

New current I1 = 3Io

This shows that tripling the voltage increases the current by factor of 3