According to Joule's law, if the potential difference across a conductor having a material of specific resistance remains constant, then the heat produced in the conductor is directly proportional to
A$\rho $
B${\rho ^2}$
C$\frac{1}{{\sqrt \rho }}$
D$\frac{1}{\rho }$
Medium
Download our app for free and get started
D$\frac{1}{\rho }$
d (d) $P = \frac{{{V^2}}}{R}$ but $R = \frac{{\rho l}}{A}$ $ \Rightarrow $ $P = \frac{{{V^2}}}{{\rho l/A}} = \frac{{A{V^2}}}{{\rho l}}$. Since $\frac{{A{V^2}}}{l}$is constant as per given conditions So $P \propto \frac{1}{\rho }$.
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 $100\, W \, bulb\, B_1$ and two $60\, W \,bulbs \,B_2$ and $B_3$, are connected to a $220\, V$ source, as shown in Figure. Now $P_1, P_2$ and $P_3$ are the output powers of the bulbs $B_1, B_2$ and $B_3$ respectively. Then
Three equal resistors connected in series across a source of $e.m.f.$ together dissipate $10\, watt$. If the same resistors are connected in parallel across the same $e.m.f.$, then the power dissipated will be .............. $watt$
A current of $2.0$ ampere passes through a cell of $e.m.f$. $1.5\, volts$ having internal resistance of $0.15\, ohm$. The potential difference measured, in $volts$, across both the ends of the cell will be
Two wires of same metal have the same length but their cross-sections are in the ratio $3:1$. They are joined in series. The resistance of the thicker wire is $10\,\Omega $. The total resistance of the combination will be ............. $\Omega$
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 uniform wire of resistance $9$ $\Omega$ is cut into $3$ equal parts. They are connected in the form of equilateral triangle $ABC$. A cell of $e.m.f.$ $2\,V$ and negligible internal resistance is connected across $B$ and $C$. Potential difference across $AB$ is ............... $V$