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• Topic:

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In the circuit shown here, what is the value of the unknown resistor R so that the total resistance of the circuit between points P and Q is also equal to

(1) 3 ohms

(2) $\sqrt{39}\text{\hspace{0.17em}}ohms$

(3) $\sqrt{69}\text{\hspace{0.17em}}ohms$

(4) 10 ohms