Question

The voltage across a resistor is found to be 1.5 V. It is also found that there is a charge of 2 Coulombs passing through the resistor within 10 seconds. What is the value of the resistor in ohms

Answer 1

Answer:

R = 7.5 Ω

Explanation:

• If the resistor is in the linear zone of operation, the resistance must obey Ohm's Law:

        $V = I*R (1)$

• By definition, the current flowing through the resistor, is equal to the charge passing through the resistor, per unit time.
• So, we can write the following expression for the current I:

        $I =\frac{\Delta Q}{\Delta t} = \frac{2C}{10s} = 0.2 A (2)$

• From (1) and (2) we can solve for R, as follows:

       $R =\frac{V}{I} = \frac{1.5V}{0.2A} = 7.5 \Omega$

• The value of the resistor is 7.5 Ω.