A voltage of 21.0V across the terminals of a device produces a current of 3.00 mA through the device. What is the resistance of the device?

Answer: 7,000 ohms

Explanation:

From the equation of ohms law V = IR

V=21 volt

I = 3 MA = 3.0*10^-3 A

So by evaluating, we have.

V = IR

21 = 3.0*10^-3 * R

Then R = 21/3.0*10^-3

R = 7,000 ohms//.