the magnitude of a charge q at the center of two equal and like charges Q so that the three charges are in equilibrium
A. Q
B. Q/2
C. Q/4
D. –Q/4
A. Q
B. Q/2
C. Q/4
D. –Q/4
D. –Q/4
If a charge q is placed at the center of the line joining two equal charges Q such that the system is in equilibrium, then the value of q is
(A)Q/2
(B)-Q/2
(C)Q/4
(D)-Q/4
A charge q is placed at one corner of the cube. The electric flux passing through any one of its face is
In the process of charging, the mass of the negatively charged body-
(A) Increases
(B) Decreases
(C) Remains Constant
(D) None of the above
A point charge +Q is placed in the vicinity of a conducting surface. Draw the electric field lines between the surface and the charge.
Two charges of 2uC and 5uC are placed 2.5 cm apart. The ratio of Coulomb's force experienced by them is
Two balls carrying charges - and +8 attract each other with a force F. If a charge of -3 is added to both the balls, then the force between then will become
A. 2F
B. F/2
C. F
D. zero
Electric charge between two bodies can be produced by
(A )Sticking
(B) Rubbing
(C) Oiling
(D) Passing AC current
The capacitance of a capacitor will decrease if we introduce a slab of:
(a) copper
(b) aluminium
(c) zinc
(d) None of these
In Young’s double slit experiment, the fringe width is found to be 0.4 mm. If the whole apparatus is immersed in water of refractive index 4/3 without disturbing the geometrical arrangement, the new fringe width will be :
i. 0.3 mm
ii. 0.4 mm
iii. 0.53 mm
iv. 0.75 mm
A parrot comes and sits on a bare high-power line. It will
A. experience a mild shock
B. experiences a strong shock
C. get killed instantaneously
D. not be affected at all
Which of the following is correct for light diverging from a point source?
(a) The intensity decreases in proportion with the distance squared.
(b) The wave front is parabolic.
(c) The intensity at the wavelength does not depend on the distance.
(d) None of these.
Three charges each equal to 2 μC are placed at the corners of an equilateral triangle. If force between any two charges is 2F, then the net force on either will be:
To observe diffraction, the size of the obstacle
a. should beX/2, where X is the wavelength.
b. should be of the order of wavelength.
c. has no relation to wavelength.
d. should be much larger than the wavelength
A dip circle is so set that it moves freely in the magnetic meridian. The angle of dip is 40°. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of 30° with the magnetic meridian. In this position, the needle will dip by the angle