In a potentiometer arrangement, a cell gives a balancing point at $75\, cm$ length of wire. This cell is now replaced by another cell of unknown emf. If the ratio of the emf's of two cells respectively is $3: 2$, the difference in the balancing length of the potentiometer wire in above two cases will be.........$cm .$
A$25$
B$255$
C$95$
D$27$
JEE MAIN 2022, Medium
Download our app for free and get started
A$25$
a $\frac{\varepsilon_{1}}{\varepsilon_{2}}=\frac{\ell_{1}}{\ell_{2}}$
$\frac{3}{2}=\frac{75 \,cm }{\ell_{2}}$
$\ell_{2}=50\, cm$
$\ell_{1}-\ell_{2}=75-50$
$=25 \,cm$
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
A $1\,m$ long copper wire carries a current of $1\,A$. If the cross section of the wire is $2.0\,mm ^{2}$ and the resistivity of copper is $1.7 \times 10^{-8}\,\Omega\,m$. the force experienced by moving electron in the wire is $\times 10^{-23}\,N$. (charge on electron $=1.6 \times 10^{-19}\,C$ )
$32$ cells, each of $emf$ $3V$, are connected in series and kept in a box. Externally, the combination shows an $emf$ of $84\, V$. The number of cells reversed in the combination is
A battery of $3.0\, V$ is connected to a resistor dissipating $0.5\, W$ of power. If the terminal voltage of the battery is $2.5\, V$ the power dissipated within the internal resistance is$.......W$
Two resistances equal at $0\,^oC$ with temperature coefficient of resistance $\alpha _1$ and $\alpha _2$ joined in series act as a single resistance in a circuit. The temperature coefficient of their single resistance will be
In potentiometer experiment when $K_1$ is closed balance length is $100\,cm$. Then what will be balancing length when $K_2$ is closed ................ $\mathrm{cm}$