In a meter bridge experiment null point is obtained at $l \mathrm{~cm}$ from the left end. If the meter…

In a meter bridge experiment null point is obtained at $l \mathrm{~cm}$ from the left end. If the meter bridge wire is replaced by a wire of same material but twice the area of across-section, then the null point is obtained at a distance
  1. $2 l \mathrm{~cm}$ from left end.
  2. $l \mathrm{~cm}$ from left end.
  3. $l / 2 \mathrm{~cm}$ from left end.
  4. $l / 4 \mathrm{~cm}$ from left end.

Solution

At null condition, $\frac{\mathrm{R}_1}{\mathrm{R}_2}=\frac{\mathrm{X}}{100-\mathrm{X}}$ This condition is independent of the crosssectional area of the wire used. $\therefore \quad$ The null point will remain the same. (i.e., $l \mathrm{~cm}$ from left end)

Asked in: MHT CET 2023 (09 May Shift 1)

Practice more Experimental Physics questions on Aicharya