At magnetic poles, the angle of dip is
Unit of magnetic dipole moment is
a) ampere meter
b) ampere/meter⁻¹
c) ampere metre²
d) ampere/metre²
A current loop placed in a magnetic field behaves like a
a) Magnetic substance
b) Magnetic pole
c) Magnetic dipole
d) all true
A steel wire of length l has a magnetic moment M .It is then bent into a semicircular arc. The new magnetic moment is
a) M
b) 2M/π
c) M/l
d) Ml
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
If the angle of dip at two places are 30° and 45° respectively, then the ratio of horizontal components of the earth’s magnetic field at the two places will be
How does the fringe width alter, if the entire Young’s double slit experimental set up is completely immersed into water ?
I. Increases
II. Decreases
III. Remains same
IV. None of these
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
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.
The SI unit of inductance is the henry. It can be written as
(a) weber/ampere
(b) volt-second/ampere
(c) joul/(ampere)²
(d) ohm-second
The self inductance of long solenoid cannot be increased by
(a) increasing its area of cross section
(b) increasing its length
(c) changing the medium with grater permeability
(d) Increasing the current through it.
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
The V-i graph for a conductor at temperature T¹ and T² are as shown in the figure. (T² - T¹) is proportional to
(a) cos θ
(b) sin θ
(c) cot 2θ
(d) tan θ