An electric charge q is placed at the centre of a cube of side a. The electric flux on one of its faces will be:
(1)
(2)
(3)
(4)
Total electric flux coming out of a unit positive charge put in air is
(1)
(2)
(3)
(4)
A cube of side l is placed in a uniform field E, where . The net electric flux through the cube is
(1) Zero
(2) l2E
(3) 4l2E
(4) 6l2E
Shown below is a distribution of charges. The flux of electric field due to these charges through the surface S is
(1)
(2)
(3)
(4) Zero
Consider the charge configuration and spherical Gaussian surface as shown in the figure. While calculating the flux of the electric field over the spherical surface, the electric field will be due to:
(1) q2 only
(2) Only the positive charges
(3) All the charges
(4) +q1 and – q1 only
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 \(y\text-\)axis is along \(\hat i\) |
2. | The electric field \(\vec E \) at all points on the \(x\text-\)axis has the same direction |
3. | The dipole moment is \(2qd\) directed along \(\hat i\) |
4. | The work has to be done to bring a test charge from infinity to the origin |
The electric field due to a uniformly charged solid sphere of radius R as a function of the distance from its centre is represented graphically by -
(1) (2)
(3) (4)
Suppose the charge of a proton and an electron differ slightly. One of them is \(\text- e\) and the other is \((e+\Delta e)\). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance \(d\) (much greater than atomic size) apart is zero, then \(\Delta e\)
1. \(10^{-20}~\text{C}\)
2. \(10^{-23}~\text{C}\)
3. \(10^{-37}~\text{C}\)
4. \(10^{-47}~\text{C}\)
Two identical charged spheres suspended from a common point by two massless strings of lengths l are initially at a distance d(d < < l) apart because of their mutual repulsion. The charges begin to leak from both the spheres at a constant rate. As a result, the spheres approach each other with a velocity v. Then, v varies as a function of the distance x between the sphere, as:
1. \(v \propto x\)
2. \(v \propto x^{\frac{-1}{2}}\)
3. \(v \propto x^{-1}\)
4. \(v \propto x^{\frac{1}{2}}\)
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
1.
2.
3.
4.