Equal potentials are applied on an iron and copper wire of same length. In order to have the same current flow in the two wires, the ratio $r$ (iron)/$r$ (copper) of their radii must be (Given that specific resistance of iron = $1.0 \times {10^{ - 7}}$ $ ohm-m$ and specific resistance of copper = $1.7 \times {10^{ - 8}}\,ohm-m$)
Easy
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
- 1In the circuit shown below, a student performing Ohm's law experiment accidently puts the voltmeter and the ammeter as shown in the circuit below. The reading in the voltmeter will be close to .......... $V$View Solution
- 2A torch battery consisting of two cells of $1.45\, volts$ and an internal resistance $0.15\,\Omega $, each cell sending currents through the filament of the lamps having resistance $1.5\,ohms$. The value of current will be ....... $A$View Solution
- 3A silver and zinc voltameter are connected in series and a current $i$ is passed through them for a time $t$ liberating $W\, gm$ of zinc. The weight of silver deposited is nearly ..............$W$View Solution
- 4$A$ Wheatstone's bridge is balanced with a resistance of $625\, \Omega$ in the third arm, where $P, Q$ and $S$ are in the $1^{st}, 2^{nd}$ and $4^{th}$ arm respectively. If $P$ and $Q$ are interchanged, the resistance in the third arm has to be increased by $51\,\Omega$ to secure balance. The unknown resistance in the fourth arm is ............. $\Omega$View Solution
- 5For ensuring dissipation of same energy in all three resistors $({R_1},\,{R_2},\,{R_3})$ connected as shown in figure, their values must be related asView Solution
- 6In the circuit shown, current through $R_2$ is zero. If $R_4 = 2\,\Omega $ and $R_3 = 4\,\Omega $ , current through $R_3$ will be ................. $\mathrm{A}$View Solution
- 7Two resistors of $6\,\Omega $ and $9\,\Omega $ are connected in series to a $120\, volt$ source. The power consumed by the $6\,\Omega $ resistor is ........... $W$View Solution
- 8View SolutionThe conductivity of a superconductor is
- 9The potential difference between $A$ and $B$ in the Figure is .............. $V$View Solution
- 10By a cell a current of $0.9\, A$ flows through $2\, ohm$ resistor and $0.3\,A$ through $7\, ohm$ resistor. The internal resistance of the cell is ............ $\Omega$View Solution