What would the overall resistance be in a series circuit if there's an unknown R, 3Ω,3Ω and a current of 2A?

R + 6 ohms

Explanation:

The current is the same in all three resistors

i = 2 amps

The problem is that the total voltage is unknown.

R = r

R1 =3 ohms

R2 = 3 ohms

The voltage drop is E = I*R

I = 2 amps

R1 = 3 ohms

R1 = 3 ohms

E = 3*2 = 6 volts

The second 3 ohm resistor also has 6 volts across it.

The total is 12 volts so far. But we know nothing more on how to solve for R.

All you can say is that the total resistance = R + 6 ohms

need to see circuit to get time constant