Strength of Electrostatic Force

Q.

In Coulombs law, the value of the constant $k$ is $\frac{1}{4{\mathrm{\pi \epsilon }}_0}$ . Here ${\epsilon }_0$ is the vacuum permittivity. But what actually is permittivity here?

Q.

Two insulated charged copper spheres A and B have their centres separated by a distance of 50 cm. What is the mutual force of electrostatic repulsion if the charge on each is $6.5\times {10}^{–7}$ 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?

Q.

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. (a) What is the distance between the two spheres? (b) What is the force on the second sphere due to the first?

Q.

SI unit electric field and electric force are

Q. Two particles $\text{A}$ and $\text{B}$ $(\text{B}$ is to the right of $\text{A})$ having charges $8\times {10}^{-6}\text{C}$ and $-2\times {10}^{-6}\text{C}$, respectively, are held fixed with separation of $20\text{cm}$. Where should a third charged particle be placed so that it does not experience a net electric force.

1. $5\text{cm}$ right of $\text{B}$
2. $5\text{cm}$ left of $\text{A}$
3. $20\text{cm}$ left of $\text{A}$
4. $20\text{cm}$ right of $\text{B}$

Q.

How do you know if a force is repulsive or attractive?

Q. Derivation of electrostatic pressure?

Q. Two particles each of mass M and carrying charge of magnitude q each are at some separation if they are in equilibrium under mutual electrostatic and gravitational forces of the order then q/m(in c/kg) is

Q.

Is the force acting between two point charges?

Q. (a) Two insulated charged copper spheres A and B have their centresseparated 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? Theradii of A and B are negligible compared to the distance ofseparation. (b) What is the force of repulsion if each sphere is charged doublethe above amount, and the distance between them is halved?

Q. Two charges of q & 6q are placed at some distance, force acting on q is $\overrightarrow{F}$, then force on 6q is

1. $-6\overrightarrow{F}$
2. $6\overrightarrow{F}$
3. $-\overrightarrow{F}$
4. $-\frac{\overrightarrow{F}}{6}$

Q. 10.Derivation of electrostatic pressure?

Q. At what separation should two equal charges, 1.0 C each, be placed, so that the force between them equals the weight of a 50 kg person?

Q. Let a total charge 2Q be distributed in a sphere of radius R, with the charge density given by $\rho \left(r\right)=kr$, where r is the distance from the centre. Two charges A and B, of -Q each, are placed on diametrically opposite points, at equal distance, a, from the centre. If A and B do not experience any force, then

1. $a=2^{\frac{-1}{4}}R$
2. $a=\frac{3R}{2^{\frac{1}{4}}}$
3. $a=\frac{R}{\sqrt{3}}$
4. $a=8^{\frac{-1}{4}}R$

Q. 105.Four point charges each of magnitude Q and mass m are moving on a circular path with uniform speed under the influence of electrostatic force .if AB=BC=CD=DA=2Rthen speed of either of them is?

Q. is electrostatic force conservative or non conseervative

Q. The electrostatic force is

1. Very strong
2. Weak
3. Always repulsive
4. Always attractive

Q. What are conservative and non conservative forces ?

Q.

Magnetic force acting on the charged particle projected perpendicular to magnetic field is proportional to r^n, where r is the radius of circular path find n

Q. effect of gravity on pressure

Q. What is gravitational field?

1. A gravitational field is a region where any other body that has mass will experience a force of attraction.
2. A gravitational field is a region where any other body that has mass will experience a force of repulsion.
3. A gravitational field is a region where any other body that has mass will experience no force of attraction.
4. A gravitational field is a region where any other body that has mass will experience no force of repulsion.

Q.

Difference between gravitational force and electrostatic force

Q.

What would happen if we touched the metal sphere on the side closer to the Van de Graaff generator?

1. The sphere gets the opposite charge as the Van de Graaff

2. The sphere gets discharged completely

3. None of the above

4. The sphere gets the same charge as the Van de Graaff

Q. Which of the following is non-conservative force?

1. Electrostatic force
2. Spring force
3. Gravitational force
4. Viscous force

Q. (a) Two insulated charged copper spheres A and B have their centres separated by a distance of 50 cm. What is the mutual force of electrostatic repulsion if the charge on each is $6.5\times {10}^{-7}$ C? The radii of A and B are negligible compared to the distance of separation.

Q. 29.The electrostatic force between 400C and 600C placed in free space is 6gf. Find the distance between remains stationary ?

Q. what is electrostatic pressure? how to derive it?

Q. The plates $\text{A}$ and $\text{B}$ of a parallel plate capacitor (PPC) as shown in the figure contain charges $\text{+Q}$ and $\text{-Q}$ respectively. The plate $\text{A}$ is fixed and the plate $\text{B}$ is connected to one end of a spring of spring constant $K$. The other end of the spring is connected to a rigid support. If the system is released from rest, what is the maximum elongation produced in the spring? The area of each plate is $\text{A}$ and the medium between the plates is air.

1. $\frac{Q^2}{4KA{\epsilon }_o}$
2. $\frac{Q^2}{2KA{\epsilon }_o}$
3. $\frac{2Q^2}{KA{\epsilon }_o}$
4. $\frac{Q^2}{KA{\epsilon }_o}$

Q.

If the force between two charged objects is to be left unchanged even though the charge on one of the object is halved keeping the other same, the original distance (d) of separation should be changed to :

1. $\frac{d}{2}$
2. $\frac{d}{\sqrt{2}}$
3. $2d$
4. $d$

Q.

how to calculate the magnitude of an electric field which can just balance a eutron of mass 3.2*10^-27kg?