A potentiometer wire of length 20 m has a resistance of 50 ohms. It is – McqOptions

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1.	A potentiometer wire of length 20 m has a resistance of 50 ohms. It is connected in series with a resistance box and a 5 V storage cell. If the potential gradient along the wire is 0.5 mV/cm, what is the resistance unplugged in the box?
A.	450 ohms
B.	400 ohms
C.	405 ohms
D.	500 ohms
Answer» B. 400 ohms

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