When resistors are connected in series does total resistance decrease or increase?

Expert Answers

An illustration of the letter 'A' in a speech bubbles

Hello!

The answer is increases. Now let's figure out why.

Ohm's law states that the current through a conductor is directly proportional to the voltage, or, in other words, that the voltage drop between endpoints of a conductor is directly proportional to the current, `Delta U = I R.` The constant `R` is called the resistance of the conductor.

When some `n` resistors of the resistances `R_i` are connected in series, the same electrical current `I` flows successively through each of them. And each resistor causes the voltage drop proportional to its resistance `R_i:`  `Delta U_i = R_i I.` Together, all resistors cause the voltage drop of `(R_1 + R_2 + ... + R_n) I,` which, in turn, means that the total resistance of a chain is `R_1 + R_2 + ... + R_n.`

Note that a resistance is always positive, so a sum is always greater than any summand.

Approved by eNotes Editorial Team

We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

  • 30,000+ book summaries
  • 20% study tools discount
  • Ad-free content
  • PDF downloads
  • 300,000+ answers
  • 5-star customer support
Start your 48-Hour Free Trial