# Common-Emitter Amplifiers

Quick question, i have a formula for finding rc (the ac resistance in the collector circuit) which is rc=RC(collector) is the parallel combination of RL I don't understand that for the example they have RC(collector resistor)= 12K ohms parallel to RL=50k ohms = 9.68K ohms.. someone explain the proper way to get 9.68k???? Thanks

Related Engineering and Comp Sci Homework Help News on Phys.org
chroot
Staff Emeritus
Gold Member
Resistors in parallel add this way:

$$\left( 50k^{-1} + 12k^{-1} \right)^{-1} = 9.68k$$

- Warren

Resistors in parallel add this way:

$$\left( 50k^{-1} + 12k^{-1} \right)^{-1} = 9.68k$$

- Warren
yeah I figured it out, just had never seen it in those terms, thanks warren!