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.

Answered by Jacob A. Physics tutor

7314 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

How can I describe the motion of an object falling, due to gravity, through a fluid? And when does the object reach terminal velocity?


What are the 'rules' of oscillation?


A car of mass 1500kg is travelling at 10 ms-1 along a horizontal road. A brake force of 3000N brings it to rest. Calculate the deceleration of the car and the distance travelled by the car whilst decelerating.


Explain the Doppler Shift Effect, and how it can be used to measure blood flow in the body.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences