Explain why the resistance of several resistors in series is increased if an additional resistor is connected in series with them? [4 marks]

2 Answers
Mar 25, 2018

Resistances are added when resistors are connected in series


In series circuit, #R_T=R_1+R_2+R_3+...+R_N#
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Therefore, any extra resistors added on to the circuit will always increase the total resistance #R_T#

Mar 25, 2018

The addition of a resistor adds to the struggle of the moving charged particles.


It is not exactly the way you asked the question. Assume there were 3 resistors: #R_1, R_2, and R_3#. Then you add #R_4#. So now there are 4 resistors in series. The original 3 still have the same resistance. But the group

#R_1, R_2, R_3, and R_4#
has more resistance than the previous group,
#R_1, R_2, and R_3#.

The term resistance is descriptive. Understanding that should help you visualize the answer to this problem.

A resistor resists the flow of current through it. The charged particles (electrons) have to struggle to get through them. So if you add one resistor to a string of them, the charged particles have that much more of a struggle to get through them all.

I hope this helps,