If two wires having resistance $R$ and $2R$. Both joined in series and in parallel then ratio of heat generated in this situation, applying the same voltage,
Medium
Download our app for free and get startedPlay store
(c) Heat $H = \frac{{{V^2}t}}{R}$ $ \Rightarrow $ $H \propto \frac{1}{R}$ (If $V$, $t$ constant)
$ \Rightarrow $ $\frac{{{H_S}}}{{{H_P}}} = \frac{{{R_P}}}{{{R_S}}} = \frac{{\left( {\frac{{R \times 2R}}{{3R}}} \right)}}{{(R + 2R)}} = \frac{2}{9}$
art

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.*

Similar Questions

  • 1
    A potentiometer is used for the comparison of $e.m.f.$ of two cells ${E_1}$ and ${E_2}$. For cell ${E_1}$ the no deflection point is obtained at $20\,cm$ and for ${E_2}$ the no deflection point is obtained at $30\,cm$. The ratio of their $e.m.f.$'s will be
    View Solution
  • 2
    A $25\, watt$, $220\, volt$ bulb and a $100\, watt$,  $220\, volt$ bulb are connected in parallel across a $220\, volt$ line. Which bulb will glow more brightly
    View Solution
  • 3
    A coil takes $15\,\min$ to boil a certain amount of water, another coil takes $20\,\min$ for the same process. Time taken to boil the same amount of water when both coil are connected in series ........... $min$
    View Solution
  • 4
    In a typical Wheatstone network, the resistances in cyclic order are $A = 10 \,\Omega $, $B = 5 \,\Omega $, $C = 4 \,\Omega $ and $D = 4 \,\Omega $ for the bridge to be balanced
    View Solution
  • 5
    $62.5 \times {10^{18}}$ electrons per second are flowing through a wire of area of cross-section $0.1\,{m^2}$, the value of current flowing will be ............ $A$
    View Solution
  • 6
    The temperature dependence of resistances of $Cu$ and undoped $Si$ in the temperature range $300-400\ K$, is best described by
    View Solution
  • 7
    The figure shows a circuit diagram of a ‘Wheatstone Bridge’ to measure the resistance $G$ of the galvanometer. The relation $\frac{P}{Q} = \frac{R}{G}$ will be satisfied only when
    View Solution
  • 8
    $V-i$ graphs for parallel and series combination of two identical resistors are as shown in figure. Which graph represents parallel combination
    View Solution
  • 9
    $AB$ is a wire of uniform resistance. The galvanometer $G$ shows no current when the length $AC = 20\,cm$ and $CB = 80\, cm$. The resistance $R$ is equal to .............. $\Omega $
    View Solution
  • 10
    $32$ cells, each of $emf$ $3V$, are connected in series and kept in a box. Externally, the combination shows an $emf$ of $84\, V$. The number of cells reversed in the combination is 
    View Solution