A dip circle is so set that it moves freely in the magnetic meridian. The angle of dip is 40°. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of 30° with the magnetic meridian. In this position, the needle will dip by the angle
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
The direction of magnetic dipole moment is always from
a) North pole to south pole
b)Away from North pole outside magnet
c) South pole to North Pole
d) all of the above
In a permanent magnet at room temperature,
(a) magnetic moment of each molecule is zero
(b) the individual molecules have non-zero magnetic moment which are all perfectly aligned
(c) domains are partially aligned
(d) domains are all perfectly aligned
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
A bar magnet of dipole moment ’m’ cut into two equal pieces transverse to its length. Dipole moment of each part is
a) Remain same
b) m/2
c) 2m
d) none of the above
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 loop placed in a magnetic field behaves like a
a) Magnetic substance
b) Magnetic pole
c) Magnetic dipole
d) all true
The fringe width (β) of a diffraction pattern and the slit width d are related as:
(a) β ∝ d
(b) β ∝1/d
(c) β ∝ √d
(d) β ∝ 1/d2
The ratio of magnetic length to geometric length of a magnet is
a) 0.084
b) 8.4
c) 80.4
d) 0.84
In Young’s experiment with one source and two slits, one of the slits is covered with black paper. Then
(A) The fringes will be darker
(B) The fringes will be narrower
(C) The fringes will be broader
(D) No fringes will be obtained and the screen will have uniform illumination
Instead of using two slits as in Young’s experiment, if we use two separate but identical sodium lamps, which of the following occur?
(a) general illumination.
(b) widely separate interference.
(c) very bright maximum.
(d) very dark minimum.
Which of the following statements is not true about Gauss’s law?
(A) Gauss’s law is true for any closed surface.
(B) The term q on the right side of Gauss’s law includes the sum of all charges enclosed by the surface.
(C) Gauss’s law is not much useful in calculating electrostatic field when the system has some symmetry.
(D) Gauss’s law is based on the inverse square dependence on distance contained in the coulomb’s law.
In YDSE, The distance between two consecutive bright and dark fringes are given by:
(a) β=λD/d
(b) β=λd/D
(c) β=λDd
(d) β=λ/Dd