When the terminals of a cell are connected by | vedclass

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

Question

(B) The terminal potential difference $V$ is given by $V = E - Ir$,where $E$ is the emf and $r$ is the internal resistance. Also,$V = IR$,so $I = V/R$

Vedclass · Accepted Answer

$2 	ext{ V}, 1 \Omega$

Vedclass · Answer

(B) The terminal potential difference $V$ is given by $V = E - Ir$,where $E$ is the emf and $r$ is the internal resistance. Also,$V = IR$,so $I = V/R$.Case $1$: $V_1 = 1.6 	ext{ V}$,$R_1 = 4 \Omega$. The current $I_1 = 1.6 / 4 = 0.4 	ext{ A}$.Using $E = V_1 + I_1 r$,we get $E = 1.6 + 0.4r$ (Equation $i$).Case $2$: $A$ second $4 \Omega$ resistor is connected in parallel,so the equivalent resistance $R_2 = (4 	imes 4) / (4 + 4) = 2 \Omega$. The new potential difference $V_2 = 1.33 	ext{ V}$.The new current $I_2 = V_2 / R_2 = 1.33 / 2 = 0.665 	ext{ A}$.Using $E = V_2 + I_2 r$,we get $E = 1.33 + 0.665r$ (Equation $ii$).Equating $(i)$ and $(ii)$: $1.6 + 0.4r = 1.33 + 0.665r$.$1.6 - 1.33 = 0.665r - 0.4r \Rightarrow 0.27 = 0.265r \Rightarrow r \approx 1 \Omega$.Substituting $r = 1 \Omega$ into $(i)$: $E = 1.6 + 0.4(1) = 2 	ext{ V}$.Thus,the emf is $2 	ext{ V}$ and the internal resistance is $1 \Omega$.

Similar Questions

$A$ $50\,V$ battery is connected across a $10\,\Omega$ resistor. The current is $4.5\,A$. The internal resistance of the battery is ............. $\Omega$.

$A$ current of $2.0 \, A$ passes through a cell of $e.m.f.$ $1.5 \, V$ having an internal resistance of $0.15 \, \Omega$. The potential difference measured,in $volts$,across the terminals of the cell will be:

In the given circuit,the internal resistance of the $18\,V$ cell is negligible. If $R_1 = 400\,\Omega$,$R_3 = 100\,\Omega$,and $R_4 = 500\,\Omega$,and the reading of an ideal voltmeter across $R_4$ is $5\,V$,then the value of $R_2$ will be ........... $\Omega$.

Three resistors $1 \Omega, 2 \Omega$ and $3 \Omega$ are connected to form a triangle. Across the $3 \Omega$ resistor,a $3 \text{ V}$ battery is connected. The current through the $3 \Omega$ resistor is: (in $\text{ A}$)

What should be the relationship between the values of the three resistors shown in the figure so that they produce equal heat energy?

Vedclass Test Series

Exam Paper Generator

Online Exam Module