Colours appears on a thin film of soap and a soap bubble is due to
(A) Interference
(B) Diffraction
(C) Polarisation
(D) Refraction
Huygens wave theory allows us to know
A) The wavelength of the wave
(B) The velocity of the wave
(C) The amplitude of the wave
(D) The propagation of wave-fronts
If a charge q is placed at the center of the line joining two equal charges Q such that the system is in equilibrium, then the value of q is
(A)Q/2
(B)-Q/2
(C)Q/4
(D)-Q/4
In the process of charging, the mass of the negatively charged body-
(A) Increases
(B) Decreases
(C) Remains Constant
(D) None of the above
Let \(ε_0\) denote the dimensional formula of the permittivity of vacuum. If M=mass, L=length, T=time and
I=electric current, then
(A) [M⁻¹L⁻³T²I]
(B) [M⁻¹L⁻³T⁴I²]
(C) [M⁻¹L²T⁻¹I⁻²]
(D) [M⁻¹L²T⁻¹I]
The distance between two-point charges is increased by 10%. The force of interaction approximately
(A) Increased by 10%
(B) Decrease by 10%
(C) Decrease by 17%
(D) Decrease by 21%
The phenomenon of diffraction can be treated as interference phenomenon if the number of coherent sources is:
(A) one
(B) two
(C) zero
(D) infinity
There is a point charge q located at the center of a cube. What is the electric flux of this point charge, through a face of the cube?
(A)q/ε₀
(B) q/6ε₀
(C) q/3ε₀
(D)It will depend upon the size of the cube
Two monochromatic light beams intensities of I and 4I are superposed. The maximum and minimum possible intensities In the resulting beam are
(A) 5I and I
(B) 5I and 3I
(C) 9I and I
(D) 9I and 3I
When a soap bubble is given an electric charge
(A) It contracts
(B) It expands
(C) Its size remains the same
(D) It expands or contracts depending upon whether the charge is positive or negative
A cylindrical bar magnet is rotated about its axis in the figure. A wire is connected from the axis and is made to touch the cylindrical surface through a contact. Then
A glass rod acquires charge by rubbing it with silk cloth. The charge on glass rod is due to :
(A) Friction
(B) Conduction
(C) Induction
(D) Radiation
A hollow copper sphere is positively charged. The electric field at its center will be
A. same as that on the surface
B. more than that on the surface
C. less than that on the surface nut not zero
D. zero
A square of side L meters lies in the x-y plane in a region where the magnetic field is given by B = B₀ (2ˆi + 3ˆj + 4kˆ) Tesla, where B₀ is constant. The magnitude of flux passing through the square Is
(A) 2B₀L² Wb
(B) 3B₀L² Wb
(C) 4B₀L² Wb
(D) √(29) B₀L² Wb
A wire of resistance 0.5 Ωm⁻¹ is bent into a circle of radius 1m. The same wire is connected across a diameter AB as shown in the fig. The equivalent resistance is
(a) Π ohm
(b) Π (Π + 2) ohm
(c) Π/( Π + 4) ohm
(d) (Π + 1) ohm