In the given figure switches $S_{1}$ and $S_{2}$ are in open condition. The resistance across $a b$ when the switches $S_{1}$ and $S_{2}$ are closed is $...\,\Omega$
A$5$
B$63$
C$10$
D$4$
JEE MAIN 2021, Diffcult
Download our app for free and get started
C$10$
c $\frac{12 \times 6}{12+6}+2+\frac{6 \times 12}{6+12}$
$\frac{72}{18}+2+\frac{72}{18}=4+2+4=10\, \Omega$
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 $5\, V$ battery with internal resistance $2\, \Omega$ and a $2\,V$ battery internal resistance $1\, \Omega$ are connected to a $10\, \Omega$ resistor as shown in the figure. The current in the $10\, \Omega$ resistor is :-
Four wires of the same diameter are connected in turn between two points, maintained at a constant potential difference. Their resistivities are; $\rho $ and $L$ (wire $1$ )., $1.2\,\rho $ and $1.2\,L$ (wire $2$ ), $0.9\,\rho $ and $0.9\,L$ (wire $3$ ) and $\rho $ and $1.5\,L$ (wire $4$ ). Rank the wires according to the rates at which energy is dissipated as heat, greatest first