The force between two charges, when placed in free space, is 5N. if they are in a medium of relative permittivity 5, the force between them will be
A. 1N
B. 25N
C. 2.5N
D. 1/5N
A. 1N
B. 25N
C. 2.5N
D. 1/5N
A. 1N
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
A point charge +Q is placed in the vicinity of a conducting surface. Draw the electric field lines between the surface and the charge.
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
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
Two charges of 2uC and 5uC are placed 2.5 cm apart. The ratio of Coulomb's force experienced by them is
Figure shows a point charge + Q, located at a distance R/2 from the centre of a spherical metal shell. Draw the electric field lines for the given system.
Two charges q and –3q are placed on x-axis separated by distance d. Where a third charge 2q should be placed such that it will not experience any force ?
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
In a Young’s double slit experiment the distance between the slit is 1 mm and the distance of screen from the slit is 1 m. If light of wavelength 6000 A is used then the fringe width is:
(a) 0.4 mm
(b) 0.5 mm
(c) 0.6 mm
(d) 0.8 mm
If a magnet is cut perpendicular its length into equal parts ,then the pole strength of each pole of the magnet
a) becomes double
b) remains same
c) becomes half
d) None of the above
In a purely resistive a.c. circuit, the current
(a) is in phase with the e.m.f.
(b) leads the e.m.f. by a difference of π radians phase
(c) leads the e.m.f. by a phase difference of π/2 radians
(d) lags behind the e.m.f. by a phase difference of π/4 radians
The electric potential V at any point (x,y,z) all in meters in space is given by V=4x2 volts. The electric field at the point (1,0,2) in volt/meter is
1. 8 along negative X axis
2. 8 along positive X axis
3. 16 along negative X axis
4. 16 along positive X axis
Two charges of 2uC and 5uC are placed 2.5 cm apart. The ratio of Coulomb's force experienced by them is
In a Wheatstone bridge, three resistors P,Q, R are connected in three arms in order and 4th arm of resistance, s, is formed by two resistors s1 and s2 connected in parallel. The condition for bridge to be balanced is, P/Q