If distance between two current- carrying wires is doubled, then force between them is
(a) halved
(b) doubled
(c) tripled
(d) quadrupled.
(a) halved
(b) doubled
(c) tripled
(d) quadrupled.
(a) halved
What is the shape of the magnet in Moving Coil Galvanometer to make the torque maximum?
a) Horse Shoe
b) Convex
c) Concave
d) None of these.
A solenoid has 1000 turns per metre length. If a current of 5A is flowing through it, then magnetic field inside the solenoid is-
Two wires of same length are shaped into a square and a circle. If they carry same current, the ratio of their magnetic moment-
a) 2:π
b)π:2
c) 4:π
d) π:4.
The current sensitivity of a Galvanometer can be increased by decreasing-
a) Magnetic field B
b) No. of turns N
c) Torsional constant k
d) Area of the coil A
Two anti-parallel conducting wires carrying currents in the ratio 2:3. What is the nature of the force acting between them?
a) Attractive
b) Repulsive
c) Both attractive and Repulsive
d) can not predict.
The coil of a moving coil galvanometer is wound over a metal frame in order to-
(a) reduce hysteresis
(b) increase sensitivity
(c) increase moment of inertia
(d) provide electromagnetic damping.
What happen when we use white light in Young’s double slit experiment.
(A) No interference pattern will form
(B) white fringes will form
(C) Central bright fringe will be white
(D) Central fringe will be coloured
When light suffers reflection at the interface between water and glass, the change of phase in the reflected wave is
(a) zero..
(b) π.
(c) π/2.
(d) 2π.
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 .
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
If the 8th bright fringe of light of wavelength \(λ_1\) coincides with the 9th bright fringe of light of the wavelength \(λ_2\) in young’s double experiment, then the possible wavelengths of visible light are
(A) 400nm and 450nm
(B) 425nm and 400nm
(C) 400nm and 425 nm
(D) 450nm and 400nm
Two copper spheres of the same radius, one solid and the other hollow, are charged to the same potential. Which will have more charge?
(a) Solid sphere
(b) Hollow sphere
(c) Both will have an equal charge
(d) None of these
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