Resistors in Series and Parallel

• What is the combined resistance of resistors in series?

  Sum of individual resistances

  
• How do you calculate total resistance in series?

  Add the individual resistances together

  
• What is the combined resistance of resistors in parallel?

  Reciprocal of the sum of reciprocals

  
• What happens to combined resistance as more resistors are added in parallel?

  Combined resistance decreases

  
• If two resistors of equal resistance are connected in parallel, what happens to the combined resistance?

  It will halve

  
• What is a common mistake when calculating parallel resistors?

  Forgetting to find the reciprocal of R

  
• What is the reciprocal of a value?

  1 divided by the value
• How do you find the reciprocal of a whole number like 2?

  It equals $\frac{1}{2}$
• What happens to the numerator and denominator of a fraction when finding its reciprocal?

  They are flipped around
• How can you calculate R from 1/R?


  Calculate 1 divided by your answer
• What button on a calculator can be used to find reciprocals?

  Reciprocal button, labelled x or 1/x
• What is the formula for the reciprocal of resistance R?

  1/R
• What is the significance of the combined resistance in a parallel circuit?

  It is less than the individual resistances
• How does the total resistance in a series circuit compare to that in a parallel circuit?

  Total resistance in series is greater