Two charges q1 and q2 are placed 30 cm apart, as shown in the figure. A third charge q3 is moved along the arc of a circle of radius 40 cm from C to D. The change in the potential energy of the system is\(\bigg(\frac{q_3}{4\pi\in_0}\bigg)k\),where k is:
Two charges q1 and q2 are placed 30 cm apart, as shown in the figure. A third charge q3 is moved along the arc of a circle of radius 40 cm from C to D. The change in the potential energy of the system is\(\bigg(\frac{q_3}{4\pi\in_0}\bigg)k\),where k is:
8q2
8q1
4q2
4q1
The Correct Option is A
Solution and Explanation
u1 =14\(\pi\in_0\)[q1q2 30×10−2+q1q2 40×10-2+q2q3 50×10-2 ]
u2 =14\(\pi\in_0\)[q1q2 30×10−2+q1q3 40×10-2+q2q310×10-2 ]
Δu= u2−u1=q2q34\(\pi\in_0\)×102[110−150]
=q2q34\(\pi\in_0\)×450×100
=q34\(\pi\in_0\)(8q2)
∴k=8q2
Therefore, the correct option is (A): 8q2
Top Questions on electrostatic potential and capacitance
- Light consisting of two wavelengths 600 nm and 480 nm is used to obtain interference fringes in a double slit experiment. The screen is placed 1.0 m away from slits which are 1.0 mm apart. (i) Calculate the distance of the third bright fringe on the screen from the central maximum for wavelength 600 nm.
- CBSE CLASS XII - 2025
- Physics
- electrostatic potential and capacitance
- A thin pencil of length \( f/4 \) is placed coinciding with the principal axis of a mirror of focal length \( f \). The image of the pencil is real and enlarged, just touches the pencil. Calculate the magnification produced by the mirror.
- CBSE CLASS XII - 2025
- Physics
- electrostatic potential and capacitance
- A ray of light is incident on a refracting face AB of a prism ABC at an angle of \( 45^\circ \). The ray emerges from face AC and the angle of deviation is \( 15^\circ \). The angle of prism is \( 30^\circ \). Show that the emergent ray is normal to the face AC from which it emerges out. Find the refraction index of the material of the prism.
- CBSE CLASS XII - 2025
- Physics
- electrostatic potential and capacitance
Two capacitors \( C_1 \) and \( C_2 \) are connected in parallel to a battery. Charge-time graph is shown below for the two capacitors. The energy stored with them are \( U_1 \) and \( U_2 \), respectively. Which of the given statements is true?
- JEE Main - 2025
- Physics
- electrostatic potential and capacitance
In a Young's double slit experiment, three polarizers are kept as shown in the figure. The transmission axes of \( P_1 \) and \( P_2 \) are orthogonal to each other. The polarizer \( P_3 \) covers both the slits with its transmission axis at \( 45^\circ \) to those of \( P_1 \) and \( P_2 \). An unpolarized light of wavelength \( \lambda \) and intensity \( I_0 \) is incident on \( P_1 \) and \( P_2 \). The intensity at a point after \( P_3 \), where the path difference between the light waves from \( S_1 \) and \( S_2 \) is \( \frac{\lambda}{3} \), is:
- JEE Main - 2025
- Physics
- electrostatic potential and capacitance
Questions Asked in NEET exam
- A microscope has an objective of focal length \(f_o = 2\) cm and an eyepiece of focal length \(f_e = 4\) cm. The tube length of the microscope is \(L = 40\) cm. If the distance of distinct vision of eye is \(D = 25\) cm, the magnification in the microscope is:
- NEET (UG) - 2025
- Optical Instruments
- Which one of the following is an example of ex-situ conservation?
- NEET (UG) - 2025
- Ex-Situ Conservation
- Which one of the following compounds can exist as cis-trans isomers?
- NEET (UG) - 2025
- Organic Chemistry
- Who proposed that the genetic code for amino acids should be made up of three nucleotides?
- NEET (UG) - 2025
- Molecular Biology
- An electron (mass \(9 \times 10^{-31}\) kg and charge \(1.6 \times 10^{-19}\) C) moving with speed \(c/100\) (\(c\) = speed of light) is injected into a magnetic field of magnitude \(9 \times 10^{-4}\) T perpendicular to its direction of motion. We wish to apply a uniform electric field \( \vec{E} \) together with the magnetic field so that the electron does not deflect from its path. (speed of light \(c = 3 \times 10^8\) m/s):
- NEET (UG) - 2025
- Electric Field
Concepts Used:
Potential Energy
The energy retained by an object as a result of its stationery position is known as potential energy. The intrinsic energy of the body to its static position is known as potential energy.
The joule, abbreviated J, is the SI unit of potential energy. William Rankine, a Scottish engineer, and physicist coined the word "potential energy" in the nineteenth century. Elastic potential energy and gravitational potential energy are the two types of potential energy.
Potential Energy Formula:
The formula for gravitational potential energy is
PE = mgh
Where,
- m is the mass in kilograms
- g is the acceleration due to gravity
- h is the height in meters
Types of Potential Energy:
Potential energy is one of the two main forms of energy, along with kinetic energy. There are two main types of potential energy and they are:
- Gravitational Potential Energy
- Elastic Potential Energy