Is it OK to write the resistance in parallel like this?

AI Thread Summary
Writing the equation for resistance in parallel is acceptable, and the method of using the reciprocal of the sum of the reciprocals is a common mnemonic. Pocket calculators simplify this process significantly compared to slide rules. It is important to ensure that the total resistance in a parallel network is always less than the smallest resistor present. The same formula for calculating total resistance can also be applied to inductors, while capacitors require a different approach. Overall, the discussion emphasizes the practicality and elegance of the parallel resistance formula.
TBert
Messages
7
Reaction score
0
I am creating an equations sheet for electronics forumlas and am wondering if it is OK to write the equation for resistance in parallel like this:
33bnUFo.png
 
Engineering news on Phys.org
TBert said:
I am creating an equations sheet for electronics forumlas and am wondering if it is OK to write the equation for resistance in parallel like this: View attachment 197492
Yes.
 
My memory rhyme was always "Reciprocal of the sum of the reciprocals"
which when pocket calculators came along in 1970's became quite handy.

Enter R,, press 1/x, press M+, repeat until all R's accounted for, press Recall Memory, press 1/x .

That's one place where a pocket calculator really outdoes a slide rule .

Your formula is much more elegant. Just make sure there's not a R0 !

have fun,.

old jim
 
  • Like
Likes Electron Spin
A bit off track but in // r's the total network R should always be smaller than the smallest resistor in ohms.

Also, a network has no P/S whereas a circuit has a power supply.

And again what Jimbo said... R total = the sum of the reciprocals, reciprocated. You can use the same formula for inductors as well, whereas capacitors you treat opposite.
 

Thread '3-terminal device external modeling'

Very basic question. Consider a 3-terminal device with terminals say A,B,C. Kirchhoff Current Law (KCL) and Kirchhoff Voltage Law (KVL) establish two relationships between the 3 currents entering the terminals and the 3 terminal's voltage pairs respectively. So we have 2 equations in 6 unknowns. To proceed further we need two more (independent) equations in order to solve the circuit the 3-terminal device is connected to (basically one treats such a device as an unbalanced two-port...
View full post »

Thread 'Question about the voltage between two charged capacitors'

suppose you have two capacitors with a 0.1 Farad value and 12 VDC rating. label these as A and B. label the terminals of each as 1 and 2. you also have a voltmeter with a 40 volt linear range for DC. you also have a 9 volt DC power supply fed by mains. you charge each capacitor to 9 volts with terminal 1 being - (negative) and terminal 2 being + (positive). you connect the voltmeter to terminal A2 and to terminal B1. does it read any voltage? can - of one capacitor discharge + of the...
View full post »

Similar threads

Van der Pauw method for sheet resistance measurement
Replies
7
Views
1K
Calculating Input/Output Impedance w/ Parallel Resistors
Replies
7
Views
2K
Capacitor charging: Where do extra electrons come from?
Replies
3
Views
754
Determining inductive reactance from a 3-phase AC circuit
Replies
17
Views
3K
How does corona discharge create leakage current?
Replies
5
Views
1K
Eliminating a differential of an e-rickshaw by using 2 motors.
Replies
3
Views
169
Need help with a parallel inductance calculation for this transformer
Replies
2
Views
2K
Can I use individual capacitor IR for parallel circuit balancing resistors?
Replies
3
Views
2K
How will the voltage, current and resistance be distributed
Replies
4
Views
1K
Simplified modeling of teledeltos paper
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top