A Daniel cell is balanced on $125\,cm$ length of a potentiometer wire. Now the cell is short-circuited by a resistance $2\, ohm$ and the balance is obtained at $100\,cm$. The internal resistance of the Daniel cell is .............. $ohm$
Medium
Download our app for free and get started
(a) $r = \left( {\frac{{{l_1} - {l_2}}}{{{l_2}}}} \right)\,R = \left( {\frac{{25}}{{100}}} \right)\,2 = 0.5\,\Omega $
Download our appand 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.*
Similar Questions
- 1A dry cell has an $e.m.f.$ of $1.5\, V$ and an internal resistance of $0.05\,\Omega $. The maximum current obtainable from this cell for a very short time interval is ................... $A$View Solution
- 2Two resistances are joined in parallel whose resultant is $\frac{6}{8}\,ohm$. One of the resistance wire is broken and the effective resistance becomes $2\,\Omega $. Then the resistance in ohm of the wire that got broken wasView Solution
- 3A certain wire has a resistance $R$. The resistance of another wire identical with the first except having twice its diameter isView Solution
- 4In a wire of circular cross-section with radius $r$, free electrons travel with a drift velocity $V$ when a current $I$ flows through the wire. What is the current in another wire of half the radius and of the same material when the drift velocity is $2V$View Solution
- 5An electric current is passed through a circuit containing two wires of the same material, connected in parallel. If the lengths and radii of the wires are in the ratio of $4/3$ and $2/3$, then the ratio of the currents passing through the wire will beView Solution
- 6Find the equivalent resistance between $P$ and $Q.$ (If each wire has a resistance $R$ )View Solution
- 7In the circuit shown below, the switch $S$ is connected to position $P$ for a long time so that the charge on the capacitor becomes $q _1 \mu C$. Then $S$ is switched to position $Q$. After a long time, the charge on the capacitor is $q _2 \mu C$.View Solution
($1$) The magnitude of $q_1$ is
($2$) The magnitude of $q _2$ is
Give the answer of question ($1$) and ($2$)
- 8Water boils in an electric kettle in $20$ minutes after being switched on. Using the same main supply, the length of the heating element should be. . . . . . .to . . . . . .. times of its initial length if the water is to be boiled in $15$ minutes.View Solution
- 9The resistance of a wire is $5\,ohm$ at $50\,^o C$ and $6\,ohm $ at $100\,^o C$. The resistance of the wire at $0\,^o C$ will be .............. $\Omega$View Solution
- 10Three resistances $P, Q, R$ each of $2 \,\,\Omega$ and an unknown resistance $S$ form the four arms of a Wheatstone bridge circuit. When a resistance of $6 \,\,\Omega$ is connected in parallel to $S$ the bridge gets balanced. What is the value of $S\,?$ ............... $\Omega$View Solution