The length of a potentiometer wire is 4 ,m an | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) The potential gradient $k$ of a potentiometer wire is given by $k = V/L$,where $V$ is the potential difference across the wire and $L$ is the tota

Vedclass · Accepted Answer

$3$

Vedclass · Answer

(D) The potential gradient $k$ of a potentiometer wire is given by $k = V/L$,where $V$ is the potential difference across the wire and $L$ is the total length of the wire.When the length of the wire is doubled $(L' = 2L)$,the potential gradient becomes $k' = V/(2L) = k/2$.The balancing condition for an unknown e.m.f. $E$ is $E = k \cdot l$,where $l$ is the balancing length.Since $E$ remains constant,$k \cdot l = k' \cdot l'$.Substituting $k' = k/2$,we get $k \cdot l = (k/2) \cdot l'$,which simplifies to $l' = 2l$.Given the initial balancing length $l = 1.5 \,m$,the new balancing length is $l' = 2 	imes 1.5 \,m = 3 \,m$.

The length of a potentiometer wire is $4 \,m$ and is connected in series with an accumulator. The e.m.f. of a cell balances against $1.5 \,m$ length of the wire. If the length of the potentiometer wire is doubled,then the new balancing length of the wire will be: (in $\,m$)

Similar Questions

$A$ voltmeter reads the potential difference across the terminals of an old battery as $1.2 \, V$,while a potentiometer reads $1.4 \, V$. The internal resistance of the battery is $40 \, \Omega$. What is the resistance of the voltmeter in $\Omega$?

$A$ $10 \ m$ long wire of resistance $20 \ \Omega$ is connected in series with a battery of e.m.f. $3 \ V$ and a resistance of $10 \ \Omega$. The potential gradient along the wire in $V/m$ is

The $e.m.f.$ of a standard cell balances across $150 \ cm$ length of a potentiometer wire. When a resistance of $2 \ \Omega$ is connected as a shunt across the cell,the balance point is obtained at $100 \ cm$. The internal resistance of the cell is .............. $\Omega$.

$A$ potentiometer consists of a wire of length $4\, m$ and resistance $10\,\Omega$. It is connected to a cell of $e.m.f.$ $2\, V$. The potential difference per unit length of the wire will be ............. $V/m$.

In a potentiometer experiment,a cell is balanced at a length of $240 \ cm$. When the cell is shunted with a resistance of $2 \ \Omega$,it is balanced at a length of $120 \ cm$. The internal resistance of the cell is .......... $\Omega$.

Vedclass Test Series

Exam Paper Generator

Online Exam Module