Ohm's Law Physics Example 4

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Example 4

medium
A resistor in a circuit has a current of 0.5 A0.5 \text{ A} flowing through it when connected to a 6 V6 \text{ V} supply. (a) What is its resistance? (b) If the voltage is doubled to 12 V12 \text{ V}, what is the new current (assuming constant resistance)?

Solution

  1. 1
    (a) R=VI=60.5=12 ΩR = \frac{V}{I} = \frac{6}{0.5} = 12 \text{ } \Omega.
  2. 2
    (b) With constant resistance: I=VR=1212=1.0 AI = \frac{V}{R} = \frac{12}{12} = 1.0 \text{ A}.

Answer

(a)  R=12 Ω;(b)  I=1.0 A(a)\; R = 12 \text{ } \Omega; \quad (b)\; I = 1.0 \text{ A}
Ohm's law (V=IRV = IR) shows a linear relationship between voltage and current for a constant resistance. Doubling the voltage doubles the current — this is the hallmark of an ohmic conductor.

About Ohm's Law

The fundamental relationship stating that the voltage (VV) across an ohmic conductor equals the current (II) flowing through it multiplied by its resistance (RR).

Learn more about Ohm's Law →

More Ohm's Law Examples

Example 1 easy

A [formula] battery is connected to a [formula] resistor. What current flows?

Example 2 medium

A heater draws [formula] from a [formula] supply. What is its resistance, and how much power does it

Example 3 medium

What voltage is needed to push [formula] through a [formula] resistor?

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