# Superposition of Electric Fields

## Trending Questions

**Q.**Four charges are arranged at the corners of a square ABCD, as shown in the figure. The force on the positive charge kept at the centre O is

- zero
- along the diagonal AC
- perpendicular to side AB
- along the diagonal BD

**Q.**

A positively charged pendulum is oscillating in a uniform electric field pointing upwards. It's time period as compared to that when it oscillates without electric field is more How?

**Q.**

A
point charge +10 μC is a distance 5 cm directly above the centre
of a square of side 10 cm, as shown in Fig. 1.34. What is the
magnitude of the electric flux through the square? (*Hint:
*Think of the square as one face of a
cube with edge 10 cm.)

**Q.**A charge Q is enclosed by a Gaussian spherical surface of radius R. If the radius is doubled, then the outward electric flux will

- be reduced to half
- remain the same
- be doubled
- become four times

**Q.**13. A wire is bent in the form of a regular pentagon of edge length a. A total of charge q is distributed over it.Find the electric field at the centre of the pentagon

**Q.**ABCD is a square of side 5cm. Charges of +50 C, -50C, and +50C are placed at A, C and D respectively.Find the resul†an t elctric field at B

**Q.**two equal and like charges when placed 5 cm apart experience a repulsive force of 0.144 newtons. The magnitude of the charge in micro-coulomb will be

**Q.**Consider three charges q1, q2, q3 each equal to q at the vertices of an equilateral triangle of side l. What is the force on a charge Q(with the same sin as q) placed at the centroid of the triangle?

**Q.**

Two fixed point charges + 4ee and +e units are separated by a distance 'a'. Where should the third point charge be placed for it to be in equilibrium?

**Q.**

A particle of mass $$m$$, charge $$Q$$and kinetic energy$$T$$enters a transverse uniform magnetic field of induction $$\overrightarrow{B}$$. After $3$ seconds the kinetic energy of the particle will be:

$$3T$$

$2T$

$$T$$

$$4T$$

**Q.**Four charges Q, q, Q and q are kept at the four corners of a square. What is the relation between Q and q so that the net force on a charge q is zero?

**Q.**Consider a regular cube with positive point charge +Q in all corners except for one which has a negative point charge −Q. Let the distance from any corner to the center of the cube be r. What is the magnitude of electric field at point P, the center of the cube?

- E=7kQr2
- E=1kQr2
- E=2kQr2
- E=6kQr2

**Q.**

The bob of a simple pendulum has a mass of 40 g and a positive charge of 4.0×10−6C. It makes 20 oscillations in 45 s. A vertical electric field pointing upward and of magnitude 2.5×104NC−1 is switched on. How much time will it now take to complete 20 oscillations?

**Q.**91.A positively charged pendulum is oscillating in a uniform electric field pointing upwards.Its time period as compared to that when it oscillates without electric field is more or less.

**Q.**

5 equal charges ‘q’ are placed at corners of a regular hexagon ABCDEF of side ‘a’ as shown. Find the net electric field at the centre O of the hexagon?

- kqa2 towards F
- 5kqa2 towards F
- 3√2kqa2 towards F
- 5√2kqa2 towards C

**Q.**

The resultant of two equal forces is equal to either of these forces. The angle between them is

$\frac{\mathrm{\pi}}{4}$

$\frac{\mathrm{\pi}}{3}$

$\frac{\mathrm{\pi}}{2}$

$\frac{2\mathrm{\pi}}{3}$

**Q.**131. A point charge is placed at distance a/2 perpendicular to the plane and above the centre of a square ofa side a .the electric flux through the square is

**Q.**41. There are two charges +2uC and -3uC.the ratio of forces acting on them will be

**Q.**For the given graph between electric field (E) at a point and distance (x) of this point from the mid-line of an infinitely long uniformly charged non-conducting thick sheet, the volume charge density of the given sheet is:-

[d is the thickness of the sheet]

- 3×10−12 C/m3
- 9×10−12 C/m3
- 12×10−12 C/m3
- 15×10−12 C/m3

**Q.**

A wire is bent in th eform of a regular hexagon and a total cahrge q is distributed uniformly on it. What is the electric field at the centre? you may answer this part without making any numerical calculations.

**Q.**29. How to find net electric field of hexagon of side 1m with six point charges -q -q -q q q q

**Q.**

A small circular ring has a uniform charge distribution. On a far off axial point distance x from the centre of the ring the electric field is proportional to?

**Q.**Three charges +q, -q and +q are kept at the corners of an equilatral triangle of side d. Find the resul†an t electric force on charge +q placed at the centriod o of the triangle

**Q.**

A string, fixed at both ends, vibrates in a resonant mode with a separation of 2.0 cm between the consecutive nodes. For the next higher resonant frequency, this separation is reduced to 1.6 cm. Find the length of the string.

**Q.**A, B, C, D corners of square of side 2a are occupied by q, -q, 2Q, Q charges resp. the fiepd at midpoint of Cd is zero. what id value of q/Q

**Q.**5 equal charges ‘q′ each are placed at the corners of a regular hexagon ABCDEF of side ‘a′ as shown. Find the net electric field at the centre O of the hexagon?

- 5kqa2 towards F
- kqa2 towards F
- 3√2kqa2 towards F
- 5√2kqa2 towards C

**Q.**Figure 1.33 shows tracks of three charged particles in a uniformelectrostatic field. Give the signs of the three charges. Which particlehas the highest charge to mass ratio?

**Q.**

A particle is acted upon by four forces simultaneously, $30N$ due east $20N$ due north $15N$ due west $40N$ due south find the resultant force of the particle?

**Q.**28.Two charged capacitor have their outer plates fixed and inner plates connected by spring of force constant k . The charge on each capacitor is q . Find the extension in the spring at equilibrium?

**Q.**two charges 2q and -3q are kept on a straight line , the number of points on this line where the electric field intensity os zero is