A) \[80\,\Omega \]
B) \[100\,\Omega \]
C) \[60\,\Omega \]
D) \[120\,\Omega \]
Correct Answer: B
Solution :
[b] \[R\to \]Resistance Potential gradient for the potentiometer wire ?AB? is \[-\frac{dV}{d\ell }=\left[ \frac{60\times R}{{{\ell }_{AB}}} \right]mv/m\] \[\therefore {{V}_{AP}}=\left( -\frac{dV}{d\ell } \right){{\ell }_{AP}}=\frac{60\times R}{1200}\times 1000mV\] \[\therefore {{V}_{AP}}=50RmV\] Also, \[{{V}_{AP}}=5\text{ }V\](for balance point at P) \[\therefore R=\frac{5}{50\times {{10}^{-3}}}=100\Omega \]You need to login to perform this action.
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