Select the correct statements from the following
(i) inside a charged or neutral conductor, electrostatic field is zero.
(ii) the electrostatic field at the surface of the charged conductor must be tangential to the surface at any point.
(iii) there is no net charge at any point inside the conductor.
(A) (i) and (ii)
(B) i) and (iii)
(C) (ii) and (iii)
(D) (i), (ii), and (iii)
(i) inside a charged or neutral conductor, electrostatic field is zero.
(ii) the electrostatic field at the surface of the charged conductor must be tangential to the surface at any point.
(iii) there is no net charge at any point inside the conductor.
(A) (i) and (ii)
(B) i) and (iii)
(C) (ii) and (iii)
(D) (i), (ii), and (iii)
(B) i) and (iii)
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 ?
Cathode rays travelling from west to east enter into region of electric field directed towards south to north in the plane of paper. The deflection of cathode rays is towards:
(A) East
(B) West
(C) North
(D) South
A charge + Q, is uniformly distributed within a sphere of radius R. Find the electric field, due to this charge distribution, at a distant point r from the centre of the sphere where :
(i) 0 < r < R
(ii) r > R
An electric dipole is placed in a uniform electric field.
(i) Show that no translatory force acts on it.
(ii) Derive an expression for the torque acting on it.
(iii) Find work done in rotating the dipole through 180°.
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
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.
An electric dipole is held in a uniform electric field.
(i) Show that the net force acting on it is zero.
(ii) The dipole is aligned parallel to the field. Find the work done in rotating it through the angle of 180°.
A parallel plate capacitor is made by stacking n equally spaced plates connected alternately. If the capacitance between any two plates is C, then the resultant capacitance is
(a) C
(b) nC
(c) (n-1)C
(d) (n+1)C
The magnetic flux linked with a coil is given by the equation Ø = 2t² + 2t + 4 weber. The magnitude of induced emf at time t=2s will be
(a) 16 V
(b) 10V
(c) 12V
(d) 8V
In a Young’s double slit experiment, the separation between the slits is 0.1 mm, the wavelength of light used is 600 nm and the interference pattern is observed on a screen 1 m away. Find the separation between bright fringes.
(A) 6.0 mm
(B) 6.6 mm
(C) 6 m
(D) 60 cm
Two sources of light are said to be coherent, when they give light waves of same
(a) amplitude and phase.
(b) wavelength and constant phase difference.
(c) intensity and wavelength.
(d) phase and speed.
What happens if one of the slits, say S1 in Young’s double , slit experiment-is covered with a glass plate which absorbs half the intensity of light from it?
(a) The bright fringes become less-bright and the dark fringes have a finite light intensity
(b) The bright fringes become brighter and the dark fringes become darker
(c) The fringe width decreases
(d) No fringes will be observed
In Young’s double slit experiment the distance between the slit and the screen is doubled and the separation between the slit is reduced to half. The fringe width:
(a) is doubled
(b) become four time
(c) is halved
(d) remain unchanged
Two sources of intensity I and 4I are used in an interference experiment . Find the intensity at points where waves from two sources superimpose with phase difference π/2 is
I. 4I
II. 6I
III. 5I
IV. 9I