Students are provided with an unknown resistor that has a constant resistance for all potential differences. The students are instructed to plot an I-V graph for the resistor.Which, if any, of the following are true for I-V graphs of ohmic devices?Amust be a horizontal lineBmust pass through the originCmust not pass through the originDnone of the above
Question
Students are provided with an unknown resistor that has a constant resistance for all potential differences. The students are instructed to plot an I-V graph for the resistor.Which, if any, of the following are true for I-V graphs of ohmic devices?Amust be a horizontal lineBmust pass through the originCmust not pass through the originDnone of the above
Solution
The correct answer is B - the I-V graph for ohmic devices must pass through the origin.
Here's why:
Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. This means that if you plot current (I) on the y-axis and voltage (V) on the x-axis, you should get a straight line that passes through the origin (0,0).
This is because when the voltage is zero, the current is also zero (since there's no potential difference to drive the current). And as you increase the voltage, the current increases proportionally, which is why you get a straight line.
So, an I-V graph for an ohmic device (like a resistor with constant resistance) is a straight line that passes through the origin. It's not a horizontal line (option A), because the current changes as the voltage changes. And it does pass through the origin (contrary to option C), because when there's no voltage, there's no current.
Therefore, option D (none of the above) is also incorrect.
Similar Questions
Students are provided with an unknown resistor that has a constant resistance for all potential differences. The students are instructed to plot an I-V graph for the resistor. What is a device that has a constant resistance for all potential differences called? A constant current device B non-ohmic device C ohmic device D constant voltage device
Students are provided with an unknown resistor that has a constant resistance for all potential differences. The students are instructed to plot an I-V graph for the resistor.Which of the following best describes the gradient of an I-V graph for such a device?Anegative and constantBpositive and constantCpositive and varyingDnegative and varying
For the resistor, the plot of V vs I (with voltage on the y axis and current on the x axis) looks like:
Slope of I-V graph of a resistor is numerically equal to:
Which of the following describes the type of graph you'd expect when plotting voltage across an electrical component vs current through the component, if it followed Ohm's Law?Question 3Select one:a.an inverse power lawb.Linearc.Quadraticd.Exponential
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