Question 1 :
Calculate the magnitude of the force between two electrons which are 
separated by a distance of $$10^{-10}m$$. If the magnitude of the charge
 is $$10^{-19}C$$ and Coulomb constant is $$10^{10}N\;m^{2}/C^{2}$$.

Question 2 :
If the electric flux entering and leaving a closed surface are respectively of magnitude $$\phi_{1}$$ and $$\phi_{2}$$ then the electric charge inside the surface will be

Question 3 :
A charge $$q_1$$ exerts a force of $$45N$$ on a charge of $$q_{2}=10^{-5} C$$ located at a point $$0.2m$$ from $$q_{1}$$. The magnitude of $$q_{1}$$ is

Question 7 :
Which of the following statements are true:A: Charge cannot exist without mass but mass can exist without charge<br/>B: Charge is invariant but mass varies with velocity<br/>C: Charge is conserved but mass alone may not be conserved

Question 8 :
Materials which allow larger currents to flow through them are called :

Question 9 :
A plane area of $$100\ {cm}^{2}$$ is placed in uniform electric field of $$100\ N/C$$ such that the angle between area vector and electric field is $$60^o$$. The electric flux over the surface is

Question 10 :
Why is electrical wiring usually covered with a layer of plastic?

Question 11 :
In one model of the electron, the electron of mass $${ m }_{ e }$$ is thought to be a uniformly charged shell of radius $$R$$ and total charge $$e$$, whose electrostatic energy $$E$$ is equivalent to its mass $${ m }_{ e }$$ via Einstein's mass energy relation $$E = { m }_{ e }{ c }^{ 2 }$$. In this model, $$R$$ is approximately ($${ m }_{ e }=9.1\times { 10 }^{ -31 }kg$$, $$c=3\times { 10 }^{ 8 }m{ s }^{ -1 }$$, $${ 1 }/{ 4 }\pi { \varepsilon }_{ 0 }=9\times { 10 }^{ 9 }Farads{ m }^{ -1 }$$, magnitude of the electron charge $$=1.6\times { 10 }^{ -19 }C$$)

Question 12 :
Two charges of 10C and -15C are separated in&#160;air by 1 m. The ratio of magnitude of force exerted by one on&#160;the other is

Question 13 :
The electric field just outside the surface of conductor of area $$A$$ and surface charge density $$\sigma$$ is given by

Question 14 :
A cone of base radius $$R$$ and height $$h$$ is located in a uniform electric field $$\overrightarrow{E}$$ parallel to its base. The electric flux entering the cone is:<br>

Question 15 :
The electric field at point P just outside the outer surface of a hollow spherical&#10;conductor of inner radius 10 cm and outer radius 20 cm has magnitude 450 N/C and is&#10;directed outward. When an unknown point charge Q is placed at the center of the&#10;sphere, the electric field at point P is still pointing outward but is now 180 N/C. What&#10;is the value of charge Q?<br/>

Question 17 :
If the electric flux entering and leaving an enclosed surface respectively is $$\phi_{1}$$ and $$\phi_{2}$$, the electric charge inside the surface will be

Question 18 :
Charge can be a multiple of $$e$$, i.e. $$ne$$. Which of the following can be a value of $$n$$?<br/>

Question 19 :
If a electric flux leaving and entering from closed surface are $$\phi$$ and $$\phi$$ respectively, then the charge associated with closed surface will be ________.

Question 20 :
The electric field in a certain region is acting radially outward and is given by $$E=Ar$$. A charge contained in a sphere of radius '$$a$$' centered at the origin of the field, will be given by :<br/>

Question 21 :
A ball of radius R carries a positive charge whose volume charge density depends only on the distance r from the ball's centre as: $$\rho=\rho_0(1-\dfrac {r}{R})$$ where $$\rho_0$$ is constant. Assume $$\epsilon$$ as the permittivity of the ball.<br/>Then the magnitude of the electric field as a function of the distance r outside the ball is given by :

Question 22 :
Consider a uniform electric field $$E=3\times 10^3&#160;\hat i \: N/C$$. What is the flux of this field through a square of $$10\ &#160;cm$$ on a side whose plane is parallel to the yz plane?

Question 23 :
A semi-circular rod of radius $$R$$ is charged uniformly with a total charge $$Q\ C$$. The electric field intensity at the centre of the curvature is<br/>(where $$K= \dfrac{1}{4 \pi \epsilon_0}$$)<br/>

Question 24 :
Two thin rods of linear charge density $$\lambda$$ Cm$$^{-1}$$ are separated by a distance d metre. The force on unit length of each rod is :

Question 25 :
Given a uniform electric field $$E=5 \times 10^3\hat i N/C$$. Find the flux of this field through a square of side $$10cm$$ on a side whose plane is parallel to YZ-plane :

Question 26 :
Consider an area element $$dS$$ at a distance $$r$$from a point P. Let $$\hat r$$be the unit vector along the outward normal to $$dS$$.If $$\alpha$$ is the angle between $$\hat r$$ and $$dS$$,the element of the solid angle subtended by the area element at P is defined as

Question 27 :
Charges $$Q_1$$ and $$Q_2$$ lie inside and outside respectively of a closed surface S. Let E be the field at any point on S and $$\phi$$ be the flux of E over S.

Question 28 :
The ratio of the energy required to set up in cube of side 10 cm uniform magnetic field of 4$${ Wb/m }^{ 2 }$$ and a uniform electric field of $$10^{ 6 }V/m$$ is:

Question 29 :
A charge $$Q$$is located at the centre of a sphere of radius $$R$$. Calculate the flux going out through the surfaceof the sphere.

Question 30 :
A charge Q is distributed uniformly in a sphere (solid). Then the electric field at any point r where r &lt; R (R is radius of the sphere) varies as

Question 31 :
Find the electric field at a distance $$x$$ from the centreinside the shell.

Question 32 :
If the charge $$+Q$$ is now at the centre of a cube of side $$2l$$, what is the total flux emerging from all the six faces of the closedsurface?

Question 33 :
Let $$E_1(r), E_2(r)$$ and $$E_3(r)$$ be the respective electric fields at a distance r from a point charge Q, an infinitely long wire with constant linear charge density $$\lambda$$, and an infinite plane with uniform surface charge density $$&#160;\sigma $$. lf $$E_1(r_0) = E_2(r_0) = E_3(r_0)$$ at a given distance $$r_0$$, then :<br/>

Question 34 :
The electric field in a region is $$E = \displaystyle \frac{5\times 10^3 x}{2}\hat{i} \ NC^{-1} cm^{-1} $$. The charge contained inside a cubical volume bounded by the surfaces $$x = 0, x = 1, y = 0, y = 1, z = 0, z = 1$$ is (where x, y, z are in cm) :