Which of the following statements is not true about Gauss’s law?
(A) Gauss’s law is true for any closed surface.
(B) The term q on the right side of Gauss’s law includes the sum of all charges enclosed by the surface.
(C) Gauss’s law is not much useful in calculating electrostatic field when the system has some symmetry.
(D) Gauss’s law is based on the inverse square dependence on distance contained in the coulomb’s law.
(A) Gauss’s law is true for any closed surface.
(B) The term q on the right side of Gauss’s law includes the sum of all charges enclosed by the surface.
(C) Gauss’s law is not much useful in calculating electrostatic field when the system has some symmetry.
(D) Gauss’s law is based on the inverse square dependence on distance contained in the coulomb’s law.
(C) Gauss’s law is not much useful in calculating electrostatic field when the system has some symmetry.
Which of the following is not a property of electric field lines?
(A) Field lines are closed and continuous curves without any breaks.
(B) Two field lines cannot cross each other.
(C) Field lines start at positive charges and end at negative charges.
(D) They do not form closed loops.
The electric flux through a closed gaussian surface depends upon
(A) Permittivity of the medium.
(B) Net charge enclosed only.
(C) Net charge enclosed and permittivity of the medium.
(D) Net charge enclosed, shape and size of the Gaussian surface and permittivity of the medium.
Five charges, q each are placed at the corners of a regular pentagon of side a.
(i) What will be the electric field at O if the charge from one of the corners (say A) is removed ?
(ii) What will be the electric field at O if the charge q at A is replaced by - q ?
A hollow copper sphere is positively charged. The electric field at its center will be
A. same as that on the surface
B. more than that on the surface
C. less than that on the surface nut not zero
D. zero
A small metallic sphere carrying charge +Q is located at the centre of a spherical cavity in a large uncharged metallic spherical shell. Write the charges on the inner and outer surfaces of the shell. Write the expression for the electric field at the point P1.
Two point charges + q and –2q are placed at the vertices ‘B’ and ‘C’ of an equilateral triangle ABC of side ‘a‘ as given in the figure. Obtain the expression for (i) the magnitude and (ii) the direction of the resultant electric field at the vertex A due to these two charges.
A charge is distributed uniformly over a ring of radius ‘a’. Obtain an expression for the electric intensity E at a point on the axis of the ring. Hence, show that for points at large distances from the ring, it behaves like a point charge.
A Galvanometer is said to be sensitive, when-
a) Small deflection for a small current
b) Small deflection for a large current
c) large deflection for a small current
d) large deflection for a large current .
When ordinary light is made incident on a quarter wave plate, the emergent light is
(a) linearly polarised.
(b) circularly polarised.
(c) unpolarised.
(d) elliptically polarised.
The colours on the soap bubble is due to
(a) Interference
(b) Diffraction
(c) Polarisation
(d) Reflection
A Solid conducting sphere having a charge Q is surrounded by an uncharged concentric conducting spherical shell. Let the potential difference between the surface of the solid sphere and the outer of the shell be V. If the shell is given a charge -3Q the new potential difference between the same two surfaces is
1. 2V
2. V/2
3. V
4. -2V
In the above diagram \(C_2\) is twice of Capacitance of \(C_1\) which is C. Find the ratio of energy stored in the combination before and after the insertion of of a dielectric constant K in both the capacitors.(Battery is disconnected)
The speed of light in air is 3 × \(10^8\) m/s. If the refractive index of glass is 1.5, find the time taken by light to travel a distance 50 cm in glass.
(a) 2.5 × \(10^{-9}\) sec.
(b) 0.5 × \(10^{-9}\) sec.
(c) 0.16 × \(10^{-9}\) sec.
(d) 3 × \(10^{-9}\) sec.
A plane wave passes through a convex lens. The geometrical shape of the wavefront that emerges is
(a) plane
(b) diverging spherical
(c) converging spherical
(d) None of these