Question 588: Electrostats & Capacitance

Question

If the potential difference across a capacitor is increased from $$5 \mathrm{~V}$$ to $$15 \mathrm{~V}$$, then the ratio of final energy to initial energy stored in the capacitor is

Accepted Answer

Initial energy $$\mathrm{W}_1=\frac{1}{2} \mathrm{CV}_1^2$$
Final energy $$\mathrm{W}_2=\frac{1}{2} \mathrm{CV}_2^2$$
$$	herefore \quad \frac{W_2}{W_1}=\left(\frac{V_2}{V_1}ight)^2=\left(\frac{15}{5}ight)^2=(3)^2=9$$

Answer

$$1: 3$$

Answer

$$27: 1$$

Answer

$$3: 1$$

Answer

$$9: 1$$

Electrostats & Capacitance

If the potential difference across a capacitor is increased from $5 \mathrm{~V} to 15 \mathrm{~V}$, then the ratio of final energy to initial energy stored in the capacitor is

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