Advertisements
Advertisements
प्रश्न
Answer the following question.
What is relative permittivity?
उत्तर
- Relative permittivity or dielectric constant is the ratio of the absolute permittivity of a medium to the permittivity of free space. It is denoted as K or εr.
i.e., K or εr = `ε/(ε_0)` - It is the ratio of the force between two point charges placed a certain distance apart in free space or vacuum to the force between the same two-point charges when placed at the same distance in the given medium.
i.e., K or εr = `"F"_"vacuum"/"F"_"medium"` - It is also called a specific inductive capacity or dielectric constant.
APPEARS IN
संबंधित प्रश्न
The electrostatic force on a small sphere of charge 0.4 μC due to another small sphere of charge − 0.8 μC in air is 0.2 N.
- What is the distance between the two spheres?
- What is the force on the second sphere due to the first?
- Two insulated charged copper spheres A and B have their centers separated by a distance of 50 cm. What is the mutual force of electrostatic repulsion if the charge on each is 6.5 × 10−7 C? The radii of A and B are negligible compared to the distance of separation.
- What is the force of repulsion if each sphere is charged double the above amount, and the distance between them is halved?
A particle of mass m and charge (−q) enters the region between the two charged plates initially moving along x-axis with speed vx (like particle 1 in the fig.). The length of plate is L and an uniform electric field E is maintained between the plates. Show that the vertical deflection of the particle at the far edge of the plate is qEL2/(2m`"v"_"x"^2`).
Find the dimensional formula of ε0.
Two charges 2.0 × 10−6 C and 1.0 × 10−6 C are placed at a separation of 10 cm. Where should a third charge be placed, such that it experiences no net force due to these charges?
Suppose an attractive nuclear force acts between two protons which may be written as F=Ce−kr/r2. Write down the dimensional formulae and appropriate SI units of C and k.
A hydrogen atom contains one proton and one electron. It may be assumed that the electron revolves in a circle of radius 0.53 angstrom (1 angstrom = 10−10 m and is abbreviated as Å ) with the proton at the centre. The hydrogen atom is said to be in the ground state in this case. Find the magnitude of the electric force between the proton and the electron of a hydrogen atom in its ground state.
Find the speed of the electron in the ground state of a hydrogen atom. The description of ground state is given in the previous problem.
Two particles A and B, each carrying a charge Q, are held fixed with a separation dbetween them. A particle C of mass m and charge q is kept at the middle point of the line AB. If it is displaced through a distance x perpendicular to AB, what would be the electric force experienced by it?
Repeat the previous problem if the particle C is displaced through a distance x along the line AB.
Two equal charges, 2.0 × 10−7 C each, are held fixed at a separation of 20 cm. A third charge of equal magnitude is placed midway between the two charges. It is now moved to a point 20 cm from both the charges. How much work is done by the electric field during the process?
How much work has to be done in assembling three charged particles at the vertices of an equilateral triangle, as shown in the figure?
Solve numerical example.
Three equal charges of 10×10-8 C respectively, each located at the corners of a right triangle whose sides are 15 cm, 20 cm, and 25cm respectively. Find the force exerted on the charge located at the 90° angle.
Write down Coulomb’s law in vector form and mention what each term represents.
Two-point charges of + 0.2 µµC and -0.2 µµC are separated by 1 o8 m. What is the value of the electric field at an axial point at a distance of 0.1 m from their mid-point?
A force F acts between sodium and chlorine ions of salt (sodium chloride) when put 1 cm apart in air. The permittivity of air and dielectric constant of water are `epsilon_0` and K respectively. When a piece of salt is put in water, electrical force acting between sodium and chlorine ions 1 cm apart is ____________.
Two positive charges ______.
For charges q1 and q2 separated by a distance R the magnitude of the electrostatic force is given by ______.
Two identical thin rings, each of radius a meter, are coaxially placed at a distance R meter apart. If Q1 coulomb and Q2 coulomb are respectively the charges uniformly spread on the two rings, the work done in moving a charge q coulomb from the centre of one ring to that of the other is ______.
Two charges of equal magnitudes kept at a distance r exert a force F on each other. If the charges are halved and distance between them is doubled, then the new force acting on each charge is ______.
A spring of spring constant 5 × 103 N/m is stretched initially by 5 cm from the unstretched position. Then the work required to stretch it further by another 5 cm is:
Coulomb's law is given by F = k q1q2 rn where n is
Identify the wrong statement in the following.
Coulomb's law correctly describes the electric force that ______
Electric charge of any system is ______.
According to Coulomb's law, which is the correct relation for the following figure?
Two point charges Q each are placed at a distance d apart. A third point charge q is placed at a distance x from the mid-point on the perpendicular bisector. The value of x at which charge q will experience the maximum Coulomb's force is ______.
The ratio of the forces between two charges placed at a certain distance apart in the air and by the same distance apart in a medium of dielectric constant K is ______.
What is meant by the statement: "Relative permittivity of water is 81"?