Question 305 of 380

Which of the following statements is false?

AKirchhoff's second law represents energy conservationBWheatstone bridge is the most sensitive when all the four resistances are of the same order of magnitudeCIn a balanced Wheatstone bridge if the cell and the galvanometer are exchanged, the null point is disturbedDA rheostat can be used as a potential divider

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Answer: (C) In a balanced Wheatstone bridge if the cell and the galvanometer are exchanged, the null point is disturbed

Let us assume {R}_{1},{R}_{2},{R}_{3}&{R}_{4} is connected balanced wheat stone bridge, such that $\dfrac{{R}_{1}}{{R}_{3}}=\dfrac{{R}_{2}}{{R}_{4}}...\left(1\right)$ as shown below,


If galvanometer and cell is exchanged, then circuit becomes as shown in below figure,



The circuit is redrawn and can be visualised as below figure,



In this case, if it is balanced, then there must be,
$\dfrac{{R}_{1}}{{R}_{2}}=\dfrac{{R}_{3}}{{R}_{4}}...\left(2\right)$

Equation \left(1\right)&\left(2\right) realises that, both equations are same, which means null point is not affected.

JEE Main Physics practice question on Current Electricity (Wheatstone Bridge), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.