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)Q/2
(B)-Q/2
(C)Q/4
(D)-Q/4
(D)-Q/4
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 charge q is placed at one corner of the cube. The electric flux passing through any one of its face is
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-point charges 2μC and 4μC are placed 2 cm apart. The ratio of the Coulomb’s force experienced by them is
(A) 1: 2
(B) 2: 1
(C) 1: 1
(D) 4: 1
In the process of charging, the mass of the negatively charged body-
(A) Increases
(B) Decreases
(C) Remains Constant
(D) None of the above
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
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:
The electric potential of earth is taken as:
(a) zero
(b) infinity
(c) unity
(d) None of these
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.
Wave theory of light cannot explain the phenomena of
1. Polarisation 2. Diffraction 3. Interference 4. Crompton effect 5. Photoelectric effect
(A) 3, 4
(C) 1 ,2
(B) 1, 4, 5
(D) 4 ,5
Two slits in Young’s double slit experiment have widths in the ratio 81:1. The ratio of the amplitudes of light waves is
(a) 3 :1
(b) 3 : 2
(c) 9 :1
(d) 6:1
In young’s double slit experiment slits are separated by 0.32mm, and screen is at 1.6m away. Then find out the least distance from the central bright fringe where the bright fringes of wavelengths as 800nm and 600nm are coinciding.
(A) 10mm
(B) 12mm
(C) 1.2mm
(D) 1.0mm
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
Unit of magnetic dipole moment is
a) ampere meter
b) ampere/meter⁻¹
c) ampere metre²
d) ampere/metre²