Effect of Dielectric Charging and Discharging of Capacitor
Capacitance

166023 A capacitor is charged and then made to discharge through a resistance. The time constant is $\tau$. In what time will the potential difference across the capacitor decrease by $10 \%$ ?

1 $\tau \ln 0.1$
2 $\tau \ln 0.9$
3 $\tau \ln \frac{10}{9}$
4 $\tau \ln \frac{11}{10}$
Capacitance

166024 A capacitor of capacity $0.1 \mu F$ connected in series to a resistor of $10 \mathrm{M} \Omega$ is charged to a certain potential and then made to discharge through the resistor. The time in which the potential will take to fall to half its original value is (Given, $\log _{10} 2=\mathbf{0 . 3 0 1 0}$ )

1 $2 \mathrm{~s}$
2 $0.693 \mathrm{~s}$
3 $0.5 \mathrm{~s}$
4 $1.0 \mathrm{~s}$
Capacitance

166025 A parallel plate air capacitor with plate area ' $A$ ' and plate separation ' $d$ ' filled with three dielectric materials of dielectric constants $K_{1}$, $K_{2}$ and $K_{3}$ is as shown in the figure. If the three dielectric materials are replaced by a single dielectric material of dielectric constant ' $K$ ' filling the entire capacitor, the capacity remains the same, then

1 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}}+\frac{1}{\mathrm{~K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
2 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
3 $\frac{1}{\mathrm{~K}}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+2 \mathrm{~K}_{3}$
4 $\mathrm{K}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}$
Capacitance

166026 A photographic flash unit consists of a xenon filled tube. It gives a flash of average power $2000 \mathrm{~W}$ for 0.04 sec. The flash is due to discharge of a fully charged capacitor of $40 \mu \mathrm{F}$. The voltage to which it is charged before a flash is given by the unit is

1 $1500 \mathrm{~V}$
2 $2000\mathrm{~V}$
3 $2500 \mathrm{~V}$
4 $3000 \mathrm{~V}$
Capacitance

166027 An air capacitor is charged with an amount of charge $q$ and dipped into an oil tank. If the oil is pumped out, the electric field between the plates of capacitor will

1 increase
2 decrease
3 remain the same
4 become zero
Capacitance

166023 A capacitor is charged and then made to discharge through a resistance. The time constant is $\tau$. In what time will the potential difference across the capacitor decrease by $10 \%$ ?

1 $\tau \ln 0.1$
2 $\tau \ln 0.9$
3 $\tau \ln \frac{10}{9}$
4 $\tau \ln \frac{11}{10}$
Capacitance

166024 A capacitor of capacity $0.1 \mu F$ connected in series to a resistor of $10 \mathrm{M} \Omega$ is charged to a certain potential and then made to discharge through the resistor. The time in which the potential will take to fall to half its original value is (Given, $\log _{10} 2=\mathbf{0 . 3 0 1 0}$ )

1 $2 \mathrm{~s}$
2 $0.693 \mathrm{~s}$
3 $0.5 \mathrm{~s}$
4 $1.0 \mathrm{~s}$
Capacitance

166025 A parallel plate air capacitor with plate area ' $A$ ' and plate separation ' $d$ ' filled with three dielectric materials of dielectric constants $K_{1}$, $K_{2}$ and $K_{3}$ is as shown in the figure. If the three dielectric materials are replaced by a single dielectric material of dielectric constant ' $K$ ' filling the entire capacitor, the capacity remains the same, then

1 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}}+\frac{1}{\mathrm{~K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
2 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
3 $\frac{1}{\mathrm{~K}}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+2 \mathrm{~K}_{3}$
4 $\mathrm{K}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}$
Capacitance

166026 A photographic flash unit consists of a xenon filled tube. It gives a flash of average power $2000 \mathrm{~W}$ for 0.04 sec. The flash is due to discharge of a fully charged capacitor of $40 \mu \mathrm{F}$. The voltage to which it is charged before a flash is given by the unit is

1 $1500 \mathrm{~V}$
2 $2000\mathrm{~V}$
3 $2500 \mathrm{~V}$
4 $3000 \mathrm{~V}$
Capacitance

166027 An air capacitor is charged with an amount of charge $q$ and dipped into an oil tank. If the oil is pumped out, the electric field between the plates of capacitor will

1 increase
2 decrease
3 remain the same
4 become zero
Capacitance

166023 A capacitor is charged and then made to discharge through a resistance. The time constant is $\tau$. In what time will the potential difference across the capacitor decrease by $10 \%$ ?

1 $\tau \ln 0.1$
2 $\tau \ln 0.9$
3 $\tau \ln \frac{10}{9}$
4 $\tau \ln \frac{11}{10}$
Capacitance

166024 A capacitor of capacity $0.1 \mu F$ connected in series to a resistor of $10 \mathrm{M} \Omega$ is charged to a certain potential and then made to discharge through the resistor. The time in which the potential will take to fall to half its original value is (Given, $\log _{10} 2=\mathbf{0 . 3 0 1 0}$ )

1 $2 \mathrm{~s}$
2 $0.693 \mathrm{~s}$
3 $0.5 \mathrm{~s}$
4 $1.0 \mathrm{~s}$
Capacitance

166025 A parallel plate air capacitor with plate area ' $A$ ' and plate separation ' $d$ ' filled with three dielectric materials of dielectric constants $K_{1}$, $K_{2}$ and $K_{3}$ is as shown in the figure. If the three dielectric materials are replaced by a single dielectric material of dielectric constant ' $K$ ' filling the entire capacitor, the capacity remains the same, then

1 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}}+\frac{1}{\mathrm{~K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
2 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
3 $\frac{1}{\mathrm{~K}}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+2 \mathrm{~K}_{3}$
4 $\mathrm{K}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}$
Capacitance

166026 A photographic flash unit consists of a xenon filled tube. It gives a flash of average power $2000 \mathrm{~W}$ for 0.04 sec. The flash is due to discharge of a fully charged capacitor of $40 \mu \mathrm{F}$. The voltage to which it is charged before a flash is given by the unit is

1 $1500 \mathrm{~V}$
2 $2000\mathrm{~V}$
3 $2500 \mathrm{~V}$
4 $3000 \mathrm{~V}$
Capacitance

166027 An air capacitor is charged with an amount of charge $q$ and dipped into an oil tank. If the oil is pumped out, the electric field between the plates of capacitor will

1 increase
2 decrease
3 remain the same
4 become zero
NEET Test Series from KOTA - 10 Papers In MS WORD WhatsApp Here
Capacitance

166023 A capacitor is charged and then made to discharge through a resistance. The time constant is $\tau$. In what time will the potential difference across the capacitor decrease by $10 \%$ ?

1 $\tau \ln 0.1$
2 $\tau \ln 0.9$
3 $\tau \ln \frac{10}{9}$
4 $\tau \ln \frac{11}{10}$
Capacitance

166024 A capacitor of capacity $0.1 \mu F$ connected in series to a resistor of $10 \mathrm{M} \Omega$ is charged to a certain potential and then made to discharge through the resistor. The time in which the potential will take to fall to half its original value is (Given, $\log _{10} 2=\mathbf{0 . 3 0 1 0}$ )

1 $2 \mathrm{~s}$
2 $0.693 \mathrm{~s}$
3 $0.5 \mathrm{~s}$
4 $1.0 \mathrm{~s}$
Capacitance

166025 A parallel plate air capacitor with plate area ' $A$ ' and plate separation ' $d$ ' filled with three dielectric materials of dielectric constants $K_{1}$, $K_{2}$ and $K_{3}$ is as shown in the figure. If the three dielectric materials are replaced by a single dielectric material of dielectric constant ' $K$ ' filling the entire capacitor, the capacity remains the same, then

1 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}}+\frac{1}{\mathrm{~K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
2 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
3 $\frac{1}{\mathrm{~K}}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+2 \mathrm{~K}_{3}$
4 $\mathrm{K}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}$
Capacitance

166026 A photographic flash unit consists of a xenon filled tube. It gives a flash of average power $2000 \mathrm{~W}$ for 0.04 sec. The flash is due to discharge of a fully charged capacitor of $40 \mu \mathrm{F}$. The voltage to which it is charged before a flash is given by the unit is

1 $1500 \mathrm{~V}$
2 $2000\mathrm{~V}$
3 $2500 \mathrm{~V}$
4 $3000 \mathrm{~V}$
Capacitance

166027 An air capacitor is charged with an amount of charge $q$ and dipped into an oil tank. If the oil is pumped out, the electric field between the plates of capacitor will

1 increase
2 decrease
3 remain the same
4 become zero
Capacitance

166023 A capacitor is charged and then made to discharge through a resistance. The time constant is $\tau$. In what time will the potential difference across the capacitor decrease by $10 \%$ ?

1 $\tau \ln 0.1$
2 $\tau \ln 0.9$
3 $\tau \ln \frac{10}{9}$
4 $\tau \ln \frac{11}{10}$
Capacitance

166024 A capacitor of capacity $0.1 \mu F$ connected in series to a resistor of $10 \mathrm{M} \Omega$ is charged to a certain potential and then made to discharge through the resistor. The time in which the potential will take to fall to half its original value is (Given, $\log _{10} 2=\mathbf{0 . 3 0 1 0}$ )

1 $2 \mathrm{~s}$
2 $0.693 \mathrm{~s}$
3 $0.5 \mathrm{~s}$
4 $1.0 \mathrm{~s}$
Capacitance

166025 A parallel plate air capacitor with plate area ' $A$ ' and plate separation ' $d$ ' filled with three dielectric materials of dielectric constants $K_{1}$, $K_{2}$ and $K_{3}$ is as shown in the figure. If the three dielectric materials are replaced by a single dielectric material of dielectric constant ' $K$ ' filling the entire capacitor, the capacity remains the same, then

1 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}}+\frac{1}{\mathrm{~K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
2 $\frac{1}{\mathrm{~K}}=\frac{1}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+\frac{1}{2 \mathrm{~K}_{3}}$
3 $\frac{1}{\mathrm{~K}}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}+2 \mathrm{~K}_{3}$
4 $\mathrm{K}=\frac{\mathrm{K}_{1} \mathrm{~K}_{2}}{\mathrm{~K}_{1}+\mathrm{K}_{2}}$
Capacitance

166026 A photographic flash unit consists of a xenon filled tube. It gives a flash of average power $2000 \mathrm{~W}$ for 0.04 sec. The flash is due to discharge of a fully charged capacitor of $40 \mu \mathrm{F}$. The voltage to which it is charged before a flash is given by the unit is

1 $1500 \mathrm{~V}$
2 $2000\mathrm{~V}$
3 $2500 \mathrm{~V}$
4 $3000 \mathrm{~V}$
Capacitance

166027 An air capacitor is charged with an amount of charge $q$ and dipped into an oil tank. If the oil is pumped out, the electric field between the plates of capacitor will

1 increase
2 decrease
3 remain the same
4 become zero