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Year: 2025
Topic: Electrostatic potential and capacitance
4.
The plates of a parallel plate capacitor are separated by d. Two slabs of different dielectric constants \(\text{K}_1\, \text{and}\, \text{K}_2\) with thickness \(\displaystyle \frac{3}{8}\text{d}\) and \(\displaystyle \frac{d}{2}\), respectively are inserted in the capacitor. Due to this, the capacitance becomes two times larger than when there is nothing between plates.
If \(\text{K}_1\,=\,1.25\, \text{K}_2\), the value of \(\text{K}_1\) is:
If \(\text{K}_1\,=\,1.25\, \text{K}_2\), the value of \(\text{K}_1\) is:
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Year: 2024
Topic: Electrostatic potential and capacitance
6.
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: The potential (V) at any axial point, at 2 m distance (r) from the centre of the dipole of dipole moment vector \(\vec{P}\) of magnitude, 4 ×10−6Cm , is ± 9 × 103V. (Take \(\frac{1}{4πϵ_0} = 9 × 10^9\) SI units).
Reason R: V = ± \(\frac{2P}{4πϵ_0r^2}\) where r is the distance of any axial point, situated at 2 m from the centre of the dipole. In the light of the above statements, choose the correct answer from the options given below:
Assertion A: The potential (V) at any axial point, at 2 m distance (r) from the centre of the dipole of dipole moment vector \(\vec{P}\) of magnitude, 4 ×10−6Cm , is ± 9 × 103V. (Take \(\frac{1}{4πϵ_0} = 9 × 10^9\) SI units).
Reason R: V = ± \(\frac{2P}{4πϵ_0r^2}\) where r is the distance of any axial point, situated at 2 m from the centre of the dipole. In the light of the above statements, choose the correct answer from the options given below:
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Year: 2024
Topic: Electrostatic potential and capacitance
8.
If the plates of a parallel plate capacitor connected to a battery are moved close to each other, then
A. the charge stored in it, increases.
B. the energy stored in it, decreases.
C. its capacitance increases.
D. the ratio of charge to its potential remains the same.
E. the product of charge and voltage increases.
Choose the most appropriate answer from the options given below:
A. the charge stored in it, increases.
B. the energy stored in it, decreases.
C. its capacitance increases.
D. the ratio of charge to its potential remains the same.
E. the product of charge and voltage increases.
Choose the most appropriate answer from the options given below:
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Year: 2023
Topic: Electrostatic potential and capacitance
11.
An electric dipole is placed at an angle of \(30^\circ\) with an electric field of intensity \(2 × 10^5NC^{−1}\). It experiences a torque equal to 4 Nm. Calculate the magnitude of charge on the dipole, if the dipole length is 2 cm.
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Year: 2022
Topic: Electrostatic potential and capacitance
14.
A capacitor of capacitance C = 900pF is charged fully by 100V battery B as shown in figure (a). Then it is disconnected from the battery and connected to another uncharged capacitor of capacitance C = 900pF as shown in figure (b). The electrostatic energy stored by the system (b) is 

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Year: 2021
Topic: Electrostatic potential and capacitance
17.
A parallel plate capacitor has a uniform electric field ' \(\vec{F}\) ' in the space between the plates. If the distance between the plates is ' d ' and the area of each plate is ' A ', the energy stored in the capacitor is ( ε0 = permittivity of free space)
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Year: 2020
Topic: Electrostatic potential and capacitance
20.
A spherical conductor of radius 10 cm has a charge of \(3.2 × 10^{−7} C\) distributed uniformly. What is the magnitude of electric field at a point 15cm from the centre of the sphere? \(\displaystyle \frac{1}{ 4\, \pi\, \epsilon_0} = 9 × 10^9 N m^2/C^2\))
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Year: 2020
Topic: Electrostatic potential and capacitance
22.
A short electric dipole has a dipole moment of \(16 \times 10^{−9}\) Cm. The electric potential due to the dipole at a point at a distance of 0.6 m from the centre of the dipole, situated on a line making an angle of \(60^\circ\) with the dipole axis is : \(\displaystyle \left(\frac{1}{4πϵ_0} = 9 × 10^9 Nm^2/C^2\right)\)
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Year: 2020
Topic: Electrostatic potential and capacitance
23.
The capacitance of a parallel plate capacitor with air as medium is 6µF . With the introduction of a dielectric medium, the capacitance becomes 30µF. The permittivity of the medium is:
(\(E_0 = 8.85 × 10^{−12}\,C^2N^{−1}m^{−2}\))
(\(E_0 = 8.85 × 10^{−12}\,C^2N^{−1}m^{−2}\))
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Year: 2018
Topic: Electrostatic potential and capacitance
25.
An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it through the same vertical distance h. The time of fall of the electron, in comparison to the time of fall of the proton is
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Year: 2018
Topic: Electrostatic potential and capacitance
27.
A toy car with charge q moves on a frictionless horizontal plane surface under the influence of a uniform electric field \(\vec{E}\). Due to the force q \(\vec{E}\), its velocity increases from 0 to 6 ms−1 in one second duration. At that instant the direction of the field is reversed. The car continues to move for two more seconds under the influence of this field. The average velocity and the average speed of the toy car between 0 to 3 seconds are respectively








