The internal resistance of a primary cell is $4\, ohm$. It generates a current of $0.2\, amp$ in an external resistance of $21\, ohm$. The rate at which chemical energy is consumed in providing the current is .............. $J/s$
A$0.42$
B$0.84$
C$5$
D$1$
Medium
Download our app for free and get started
D$1$
d (d) $\frac{H}{t} = {i^2}R$. Here total $R = (21 + 4) = 25\,\,\Omega $
$ \Rightarrow $ Rate of energy consumed $ = 0.2 \times 0.2 \times 25$$ = \,1\,\,J/s$
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.*
$A$ total charge $Q$ flows across a resistor $R$ during a time interval $= T$ in such a way that the current vs. time graph for $0 \rightarrow T$ is like the loop of a sin curve in the range $0 \rightarrow \pi$ . The total heat generated in the resistor is
An electric wire of length ‘$I$’ and area of cross-section $a$ has a resistance $R\, ohms$. Another wire of the same material having same length and area of cross-section $4a$ has a resistance of
A copper wire of resistance $R$ is cut into ten parts of equal length. Two pieces each are joined in series and then five such combinations are joined in parallel. The new combination will have a resistance
A uniform wire of resistance $R$ is uniformly compressed along its length, until its radius becomes $n$ times the original radius. Now resistance of the wire becomes
Two identical heater filaments are connected first in parallel and then in series. At the same applied voltage, the ratio of heat produced in same time for parallel to series will be: