There is a uniform electric field of strength 10³ V/m along the y-axis. A body of mass 1g and charge 10^–6C is projected into the field from the origin along the positive x-axis with a velocity 10m/s. Its speed in m/s after 10s is (Neglect gravitation) 

(1) 10

(2) $5\sqrt{2}$

(3) $10\sqrt{2}$

(4) 20

Four-point +ve charges of the same magnitude (Q) are placed at four corners of a rigid square frame as shown in the figure. The plane of the frame is perpendicular to Z-axis. If a –ve point charge is placed at a distance z away from the above frame (z<<L) then 

(1) – ve charge oscillates along the Z-axis.

(2) It moves away from the frame

(3) It moves slowly towards the frame and stays in the plane of the frame

(4) It passes through the frame only once.

X and Y are large, parallel conducting plates close to each other. Each face has an area A. X is given a charge Q. Y is without any charge. Point A, B, and C are as shown in the figure. Find the incorrect option.

1.  the field at B is $\frac{\mathrm{Q}}{2{\mathrm{\epsilon }}_0\mathrm{A}}$

2.  the field at B is $\frac{\mathrm{Q}}{{\mathrm{\epsilon }}_0\mathrm{A}}$

3.  the fields at A, B and C are of the same magnitude

4.  the fields at A and C are of the same magnitude but in opposite directions

A point charge q is placed at a distance a/2 directly above the centre of a square of side a. The electric flux through the square is:

1. $\frac{q}{{\epsilon }_0}$

2. $\frac{q}{\pi {\epsilon }_0}$

3. $\frac{q}{4{\epsilon }_0}$ 

4. $\frac{q}{6{\epsilon }_0}$

Point charges +4q, –q and +4q are kept on the x-axis at points x = 0, x = a and x = 2a respectively, then 

(1) Only -q is in stable equilibrium

(2) None of the charges are in equilibrium

(3) All the charges are in unstable equilibrium

(4) All the charges are in stable equilibrium

Two-point charges +q and –q are held fixed at (–d, 0) and (d, 0) respectively of a (x, y) coordinate system. Then 

(1) E at all points on the y-axis is along $\hat{i}$

(2) The electric field $\overrightarrow{E}$ at all points on the x-axis has the same direction

(3) Dipole moment is 2qd directed along $\hat{i}$

(4) Work has to be done in bringing a test charge from infinity to the origin

One metallic sphere A is given positive charge whereas another identical metallic sphere B of exactly same mass as of A is given equal amount of negative charge. Then 

(1) Mass of A and mass of B is the same

(2) Mass of A is more

(3) Mass of B is less

(4) Mass of B is more

A point charge q is placed over a horizontal square of side L at a normal distance of L/4 from its centre. Electric flux through the square is 

1. $\mathrm{\varphi }=\frac{\mathrm{q}}{6{\mathrm{\epsilon }}_0}$

2. $\mathrm{\varphi }<\frac{\mathrm{q}}{6{\mathrm{\epsilon }}_0}$

3. $\frac{\mathrm{q}}{6{\mathrm{\epsilon }}_0}<\mathrm{\varphi }<\frac{\mathrm{q}}{{\mathrm{\epsilon }}_0}$

4. $\mathrm{\varphi }>\frac{\mathrm{q}}{6{\mathrm{\epsilon }}_0}$

Consider the charge configuration and spherical Gaussian surface as shown in the figure. When calculating the flux of the electric field over the spherical surface, the electric field will be due to:

An electron enters an electric field with its velocity in the direction of the electric lines of force. Then 

(1) The path of the electron will be a circle

(2) The path of the electron will be a parabola

(3) The velocity of the electron will decrease

(4) The velocity of the electron will increase