In Young’s double slit experiment, if the separation
between coherent sources is halved and the
distance of the screen from the coherent sources is
doubled, then the fringe width becomes :
(1) double
(2) half
(3) four times
(4) one-fourth

The capacitance of a parallel plate capacitor with
air as medium is 6 µF. With the introduction of a
dielectric medium, the capacitance becomes 30 µF.
The permittivity of the medium is :
(``e_0 =8.85 \times 10^{-12} C^2 N^{-1} m^{-2} ``)
(1) 0.44×``10^{-13} C^2 N^{-1} m^{-2}``
(2) ``1.77×10^{-12} C^2 N^{-1} m^{-2}``
(3)`` 0.44 × 10^{-10} C^2 N^{-1} m^{-2}``
(4) ``5.00 C^2 N^{-1} m^{-2}``

Dimensions of stress are :
(1) ``[ M L T^{-2} ]``
(2) ``[ M L^2 T^{-2} ]``
(3) ``[ M L^0 T^{-2} ]``
(4) ``[ M L^{-1}T^{-2} ]``

Assume that light of wavelength 600 nm is coming
from a star. The limit of resolution of telescope
whose objective has a diameter of 2 m is :
(1) ``3.66×10^{-7}`` rad
(2)`` 1.83×10^{-7}`` rad
(3)`` 7.32×10^{-7}`` rad
(4)`` 6.00×10^{-7}`` rad

A series LCR circuit is connected to an ac voltage
source. When L is removed from the circuit, the
phase difference between current and voltage
is ``\frac{\pi}{3}``. If instead C is removed from the circuit,
the phase difference is again
``\frac{\pi}{3}`` between current
and voltage. The power factor of the circuit is :
(1) zero
(2) 0.5
(3) 1.0
(4) -1.0

A short electric dipole has a dipole moment of
16×10-9 C m. The electric potential due to the
dipole at a point at a distance of 0.6 m from the
centre of the dipole, situated on a line making an
angle of 608 with the dipole axis is :
``(\frac{1}{4 \pi \epsilon_0} = 9 \times 10^9 \frac{N m^2}{C^2})``
(1) 50 V
(2) 200 V
(3) 400 V
(4) zero

An iron rod of susceptibility 599 is subjected to a
magnetising field of 1200 A m-1. The
permeability of the material of the rod is :
(µ
0
=4π×``10^{-7}`` T m A-1)
(1) 2.4π×``10^{-4}`` T m A-1
(2) 8.0×``10^{-5}`` T m A-1
(3) 2.4π×``10^{-5}`` T m A-1
(4) 2.4π×``10^{-7}`` T m A-1

A long solenoid of 50 cm length having 100 turns
carries a current of 2.5 A. The magnetic field at
the centre of the solenoid is :
(``µ_0``
=4π×``10^{-7}`` T m A-1)
(1) 6.28×``10^{-4}`` T
(2) 3.14×``10^{-4}`` T
(3) 6.28×``10^{-5}`` T
(4) 3.14×``10^{-5}`` T

A charged particle having drift velocity of
7.5×``10^{-4}`` m s-1 in an electric field of
``3×10^{-10} Vm^{-1}``, has a mobility in m2 V-1 s-1
of :
(1) 2.25×``10^{15}``
(2) 2.5×``{10^6}``
(3) 2.5×``10^{-6}``
(4) 2.25×``10^{-15}``

The quantities of heat required to raise the
temperature of two solid copper spheres of radii
``r_1 \text{ and } r_2 (r_1 =1.5 r_2)`` through 1 K are in the
ratio :
(1)
``\frac{27}{8}``
(2)
``\frac{9}{4}``
(3)
``\frac{3}{2}``
(4)
``\frac{5}{3}``

An electron is accelerated from rest through a
potential difference of V volt. If the de Broglie
wavelength of the electron is 1.227×``10^{-2}`` nm, the
potential difference is :
(1) 10 V
(2) ``10^2`` V
(3) ``10^3`` V
(4)`` 10^4`` V

Taking into account of the significant figures, what
is the value of 9.99 m-0.0099 m ?
(1) 9.9801 m
(2) 9.98 m
(3) 9.980 m
(4) 9.9 m

A ball is thrown vertically downward with a
velocity of 20 m/s from the top of a tower. It hits
the ground after some time with a velocity of
80 m/s. The height of the tower is : (g=10 m/``s^2``)
(1) 360 m
(2) 340 m
(3) 320 m
(4) 300 m

A capillary tube of radius r is immersed in water
and water rises in it to a height h. The mass of
the water in the capillary is 5 g. Another capillary
tube of radius 2r is immersed in water. The mass
of water that will rise in this tube is :
(1) 2.5 g
(2) 5.0 g
(3) 10.0 g
(4) 20.0 g

A resistance wire connected in the left gap of a
metre bridge balances a 10 Ω resistance in the
right gap at a point which divides the bridge wire
in the ratio 3 : 2. If the length of the resistance
wire is 1.5 m, then the length of 1 Ω of the
resistance wire is :
(1)`` 1.0×10^{-2} m``
(2) 1.0×10-1 m
(3) 1.5×10-1 m
(4) ``1.5×10^{-2}`` m