Question

There are a large number of cells available, each marked $(6 \,V , 0.5 \,\Omega)$ to be used to supply current to a device of resistance $0.75 \,\Omega$, requiring $24 \,A$ current. How should the cells be arranged, so that power is transmitted to the load using minimum number of cells?

• A. Six rows, each containing four cells
• B. Four rows, each containing six cells
• C. Four rows, each containing four cells
• D. Six rows, each containing six cells

Answer 1

Answer: (B)

$E=6\, V$
$r=0.5\, \Omega$
$R=0.75\, \Omega$
$i=24 \,\Omega$
$S(0.5)=P(0.75)$
$2 s=3 \,p$
$i=\frac{P S E}{S r+P R}$
$24=\frac{P\left(\frac{3}{2} P\right) 6}{15 P}$
$P=4$ rows
$S=6$ cells