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.
(a) reduce hysteresis
(b) increase sensitivity
(c) increase moment of inertia
(d) provide electromagnetic damping.
(d) provide electromagnetic damping
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
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.
If distance between two current- carrying wires is doubled, then force between them is
(a) halved
(b) doubled
(c) tripled
(d) quadrupled.
To convert a moving coil galvanometer into on ammeter of given range, we must connect:
(a) A suitable low resistance in series
(b) A suitable low resistance in parallel
(c) A suitable high resistance in parallel
(d) A suitable high resistance in series
The magnetic flux linked with a coil is given by an equation Φ = 5t² + 2t + 3. The induced e.m.f. in the coil at the third second will be
(A) 32 units
(B) 54 units
(C) 40 units
(D) 65 units
A current carrying small loop behaves like a small magnet. If A be its area and M its magnetic moment, the current in the loop will be
a) M/A
b) A/M
c) MA
d) A²M
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)
A current loop placed in a magnetic field behaves like a
a) Magnetic substance
b) Magnetic pole
c) Magnetic dipole
d) all true
Charge in motion within the Gaussian surface gives changing physical quantity
(A) Electric field
(B) Electric flux
(C) Charge
(D) Gaussian surface area
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
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