The energy stored in the capacitor as shown in Fig. (a) is 4.5 × 10-6 J. If the battery is replaced by another capacitor of 900 pF as shown in Fig. (b), then the total energy of system is

Question

The energy stored in the capacitor as shown in Fig. (a) is 4.5 × 10-6 J. If the battery is replaced by another capacitor of 900 pF as shown in Fig. (b), then the total energy of system is (A) 4.5 × 10-6 J (B) 2.25 × 10-6 J (C) zero (D) 9 × 10-6 J

Tardigrade Admin · Accepted Answer

Energy stored in the capacitor in Fig (a)

\frac{1}{2} \frac{Q ^{2}}{C} = 4.5 \times 1 0^{- 6} J

If battery in Fig. (a) is replaced by capacitor in Fig. (b),
total energy stored

= \frac{1}{2} (\frac{1}{2} \frac{Q ^{2}}{C})

= \frac{1}{2} \times 4.5 \times 1 0^{- 6}

= 2.25 \times 1 0^{- 6} J

Q. The energy stored in the capacitor as shown in Fig. (a) is $4.5 \times 1 0^{- 6} J$ . If the battery is replaced by another capacitor of $900 pF$ as shown in Fig. (b), then the total energy of system is

$4.5 \times 1 0^{- 6} J$

$2.25 \times 1 0^{- 6} J$

zero

$9 \times 1 0^{- 6} J$

Energy stored in the capacitor in Fig (a)
$\frac{1}{2} \frac{Q ^{2}}{C} = 4.5 \times 1 0^{- 6} J$
If battery in Fig. (a) is replaced by capacitor in Fig. (b),
total energy stored
$= \frac{1}{2} (\frac{1}{2} \frac{Q ^{2}}{C})$
$= \frac{1}{2} \times 4.5 \times 1 0^{- 6}$
$= 2.25 \times 1 0^{- 6} J$

Q. The energy stored in the capacitor as shown in Fig. (a) is 4.5×10−6J. If the battery is replaced by another capacitor of 900pF as shown in Fig. (b), then the total energy of system is

4.5×10−6J

2.25×10−6J