Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Resistors
Name: Mike D.
Status: Student
Age: 20s
Location: N/A
Country: N/A
Date: Around 2001

Why are resistors used if they dissipate energy? Isn't there a better way to design a circuit?

Resistors perform many functions in an electrical circuit: 1. The dissipation of electrical energy may be exactly what is desired, as in the case of incandescent lights, and electric heaters. 2. It may be necessary to know/control/vary the electrical current in a circuit. This is easily done with a resistor and Ohm's Law V(voltage)= i(current)xR(resistance). 3. It may be desired to have resistances that cannot be controlled, e.g. resistance due to connecting wires of varying lengths from circuit be negligible. This can be done by using a ballast resistor. The alternative of using superconducting circuit wires in not practical in most cases. 4. It may be desired to divide an electric current into several branches. This is done by using resistors in parallel. 5. It may be desired to have an alternating current curcuit that has a resonant frequency response. This is done by using combinations of resistors, capacitors, and induction coils. The list is long.

There may be alternative ways of designing circuits without resistors, but it's hard to see how to do that as effectively and cheaply as a resistor.

Vince Calder

We have many fundamental components besides for the resistor. Chips can replace larger circuits by using transistors and such, and avoiding bulkier components such as resistors. However, resistors are cheap.

Hope this helps

Click here to return to the Computer Science Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory