If the galvanometer shows no deflection, then the value of R for the circuit shown in the figure is ( length AB = 100 cm )

30 ohms

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60 ohms

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10 ohms

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120 ohms

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Solution

The correct option is B 60 ohms
Length $A B = 100$ cm
$\frac{R \times R}{R + R} = \frac{R^{2}}{2 R} = \frac{R}{2}$
$\frac{10}{R / 2} = \frac{25}{75}$ (Using wheatstone bridge)
or, $\frac{20}{R} = \frac{1}{3}$
or, $R = 60$ cm.

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If the galvanometer shows no deflection, then the value of R for the circuit shown in the figure is ( length AB = 100 cm )

The correct option is B 60 ohmsLength AB=100 cmR×RR+R=R22R=R210R/2=2575 (Using wheatstone bridge)or, 20R=13or, R=60 cm.

The correct option is B 60 ohms
Length $A B = 100$ cm
$\frac{R \times R}{R + R} = \frac{R^{2}}{2 R} = \frac{R}{2}$
$\frac{10}{R / 2} = \frac{25}{75}$ (Using wheatstone bridge)
or, $\frac{20}{R} = \frac{1}{3}$
or, $R = 60$ cm.