Draw the I-V curves of both an ideal resistor and a filament bulb. Explain the key features of both.

Plot: I-V curve of an ideal resistor is a straight line with a positive gradient passing through (0,0)The I-V curve of an ideal resistor is a straight line because ideal resistors strictly obey Ohm's law (V = IR). The gradient is constant because the resistance does not change. The line should pass through the origin because no current can flow with zero applied potential difference.Plot: The I-V curve of a filament bulb is a sub-linear line passing through (0,0)The I-V curve of a filament bulb has a decreasing gradient as voltage increases. This is because as more voltage (or current) is applied, the temperature of the filament increases. The atoms making up the filament will therefore increase in energy and an increase in their movement. The rate of collisions between the electrons and the lattice will increase. The resistance of the filament therefore increases. The line should still pass through the origin because no current can flow with zero applied voltage.

JA
Answered by Jacob A. Physics tutor

8207 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

Can you explain the Work-Energy principle and how you can apply it in a simple situation such as a box sliding down a rough slope?


A 80kg man is hanging from two 1.5m ropes that lie at 60 degrees from the horizontal. What is the tension in each rope required to prevent the man from dropping?


Describe and explain the first stages of the life cycle of a star before it reaches the main sequence.


Sphere A (mass m), moving with speed 3v, collides with sphere B (mass 2m) which is moving in the opposite direction with speed v. The two spheres then combine, calculate the resulting velocity of the combined spheres.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning