In meter bridge experiment for measuring unknown resistance ' $S$ ', the null point is obtained at a distance $30 cm$ from the left side as shown at point $D$. If $R$ is $5.6 k \Omega$, then the value of unknown resistance ' $S$ ' will be $\Omega .$
A$240$
B$24$
C$48$
D$2400$
JEE MAIN 2022, Medium
Download our app for free and get started
D$2400$
d $\frac{ S }{30}=\frac{5.6 \times 10^{3}}{70}$
$S =\frac{3}{7} \times 5.6 \times 10^{3}=2400$
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 potentiometer $PQ$ is set up to compare two resistances as shown in the figure. The ameter $A$ in the circuit reads $1.0\, A$ when two way key $K_3$ is open. The balance point is at a length $l_1\, cm$ from $P$ when two way key $K_3$ is plugged in between $2$ and $1$ , while the balance point is at a length $l_2\, cm$ from $P$ when key $K_3$ is plugged in between $3$ and $1$ . The ratio of two resistances $\frac{{{R_1}}}{{{R_2}}}$ is found to be
The resistances of the platinum wire of a platinum resistance thermometer at the ice point and steam point are $8 \Omega$ and $10 \Omega$ respectively. After inserting in a hot bath of temperature $400^{\circ} \mathrm{C}$, the resistance of platinum wire is:
To find the resistance of a galvanometer by the half deflection method the following circuit is used with resistances $R_1 = 9970\,\Omega,$ $R_2 = 30\,\Omega$ and $R_3 = 0\,\Omega.$ The deflection in the galvanometer is $d$. With $R_3 = 107\,\Omega$ the deflection changed to $\frac {d}{2}$The galvanometer resistance is approximately ............... $\Omega$
This question has Statement $1$ and Statement $2.$ Of the four choices given after the Statements, choose the one that best describes the two Statements.
Statement $1 :$ The possibility of an electric bulb fusing is higher at the time of switching $ON.$
Statement $2:$ Resistance of an electric bulb when it is not lit up is much smaller than when it is lit up.
Two resistors of resistance, $100\,\Omega$ and $200\,\Omega$ are connected in parallel in an electrical circuit. The ratio of the thermal energy developed in $100\,\Omega$ to that in $200\,\Omega$ in a given time is:
In the following $'I'$ refers to current and other symbols have their usual meaning, Choose the option that corresponds to the dimensions of electrical conductivity
A potentiometer wire $AB$ having length $L$ and resistance $12\, r$ is joined to a cell $D$ of $emf$ $\varepsilon $ and internal resistance $r$. A cell $C$ having $emf$ $\varepsilon /2$ and internal resistance $3r$ is connected. The length $AJ$ at which the galvanometer as shown in figure shows no deflection is
$10\, Cells$, each of $emf$ $'E'$ and internal resistance $'r'$, are connected in series to a variable external resistance. Figure shows the variation of terminal potential difference of their combination with the current drawn from the combination.$Emf$ of each cell is ................ $V$
A letter $A$ is constructed of a uniform wire with resistance $1.0\,\Omega \,per\,cm$. The sides of the letter are $20\, cm$ and the cross piece in the middle is $10\, cm$ long. The apex angle is $60^o$. The resistance between the ends is .............. $\Omega$