Answer:
a. 1.2 ohms
b. 6 ohms
Step-by-step explanation:
As with any problem involving evaluation of a formula, substitute the given values for the corresponding variables and do the arithmetic.
a.
[tex]R=\dfrac{1}{\dfrac{1}{R_1}+\dfrac{1}{R_2}}=\dfrac{1}{\dfrac{1}{2}+\dfrac{1}{3}}=\dfrac{1}{\left(\dfrac{5}{6}\right)}=\boxed{\dfrac{6}{5}=1.2}[/tex]
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b.
[tex]R=\dfrac{1}{\dfrac{1}{R_1}+\dfrac{1}{R_2}}=\dfrac{1}{\dfrac{1}{10}+\dfrac{1}{15}}=\dfrac{1}{\left(\dfrac{5}{30}\right)}=\dfrac{30}{5}=\boxed{6}[/tex]
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Comment on these problems
You will notice that the values in part (b) are 5 times those in part (a). So, it is no surprise that the answer in part (b) is 5 times the answer in part (a).
