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:
(A)double
(B)half
(C)four times
(D)one-fourth

The capacitance of a parallel plate capacitor with air as medium is `` 6\, \mu F `` . With the introduction of a dielectric medium, the capacitance becomes 30 `` \mu F. `` The permittivity of the medium is :
`` (\epsilon_0 = 8.85 \times 10^{-12} C^2N^{-1}m^{-2} `` )
(A) `` 0.44 \times 10^{-13} C^2 N^{-1}m^{-2} ``
(B) `` 1.77 \times 10^{-12} C^2 N^{-1}m^{-2} ``
(C) `` 0.44 \times 10^{-10} C^2 N^{-1}m^{-2} ``
(D) `` 5.00 \,C^2 N^{-1}m^{-2} ``

Dimensions of stress are:
(A) `` [MLT^{-2}] ``
(B) `` [ML^2T^{-2}] ``
(C) `` [M^1L^{-1}T^{-2}] ``
(D) `` [ML^{-2} 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 :
(A) `` 3.66 \times 10^{-7} \,rad ``
(B) `` 1.83 \times 10^{-7} \,rad ``
(C) `` 7.32 \times 10^{-7} \,rad ``
(D) `` 6.00 \times 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 :
(A)zero
(B)0.5
(C)1.0
(D)-1.0

A short electric dipole has a dipole moment of `` 16 \times 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 60° with the dipole axis is :
`` (\frac {1}{4\pi \epsilon_o}= 9 \times 10^9 N\,m^2/C^2) ``
(A) `` 50\,V ``
(B) `` 200\,V ``
(C) `` 400\,V ``
(D)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 :
`` (\mu_o = 4\pi \times 10^{-7} T\,m\,A^{-1}) ``
(A) `` 2.4 \pi \times 10^{-4} T\,m\,A^{-1} ``
(B) `` 8.0 \pi \times 10^{-5} T\,m\,A^{-1} ``
(C) `` 2.4 \pi \times 10^{-5} T\,m\,A^{-1} ``
(D) `` 2.4 \pi \times 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 :
`` (\mu_o = 4\pi \times 10^{-7} T\,m\,A^{-1}) ``
(A) `` 6.28 \times 10^{-4}T ``
(B) `` 3.14 \times 10^{-4}T ``
(C) `` 6.28 \times 10^{-5}T ``
(D) `` 3.14 \times 10^{-5}T ``

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

The quantities of heat required to raise the temperature of two solid copper spheres of radii `` r_1 `` and `` r_2 `` `` (r_1 = 1.5 \,r_2 `` ) through 1 K are in the ratio :
(A) `` \frac {27}{8} ``
(B) `` \frac {9}{4} ``
(C) `` \frac {3}{2} ``
(D) `` \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 \times 10^{-2}nm `` , the potential difference is :
(A) `` 10 `` V
(B) `` 10^2 `` V
(C) `` 10^3 `` V
(D) `` 10^4 `` V

Taking into account of the significant figures, what is the value of `` 9.99 \,m - 0.0099 \,m `` ?
(A)9.9801 m
(B)9.98 m
(C)9.980 m
(D)9.9 m

A ball is thrown vertically downward with a velocity of 20m/s from the top of a tower. It hits the ground after some time with a velocity of 80m/s. The height of the tower is : (g = `` 10m/s^2 `` )
(A)360 m
(B)340 m
(C)320 m
(D)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 `` 2\,r `` is immersed in water. Themass of water that will rise in this tube is :
(A)2.5 g
(B)5.0 g
(C)10.0 g
(D)20.0 g

A resistance wire connected in the left gap of a metre bridge balances a `` 10\, \Omega `` 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 `` \Omega `` of the resistance wire is:
(A) `` 1.0 \times 10^{-2} m ``
(B) `` 1.0 \times 10^{-1} m ``
(C) `` 1.5 \times 10^{-1} m ``
(D) `` 1.5 \times 10^{-2} m ``