Which of the following is incorrect for displacement current
A. Displacement current exists only when electric field changes with time
B. Displacement current obeys ohm's law
C. Displacement current produces magnetic field just like conduction current
D. Unlike conduction current, displacement current does not involve the flow of electrons through a conductor
B
D
A
C
In a Young's double slit experiment, the slit separation is 1.5 mm . The setup is illuminated simultaneously by light of wavelengths $6000 \mathop {\rm{A}}\limits^{\rm{o}}$ and $8000 \mathop {\rm{A}}\limits^{\rm{o}}$. The screen is placed at a distance of 1.5 m from the slits. It is observed that at a certain point $P$ on the screen which is 4.8 mm from the central maximum, fringes due to both the wavelengths coincide.
Which of the following options are correct?
A. Light of wavelength $6000\mathop {\rm{A}}\limits^{\rm{o}}$ produces a dark fringe and light of wavelength $8000 \mathop {\rm{A}}\limits^{\rm{o}}$ produces a bright fringe at P
B. Light of wavelength $6000 \mathop {\rm{A}}\limits^{\rm{o}}$ produces a bright fringe and light of wavelength $8000 \mathop {\rm{A}}\limits^{\rm{o}}$ produces a dark fringe at P
C. Light of wavelength $6000\mathop {\rm{A}}\limits^{\rm{o}}$ and light of wavelength $8000 \mathop {\rm{A}}\limits^{\rm{o}}$ both produce a dark fringe at P
D. Light of wavelength $6000 \mathop {\rm{A}}\limits^{\rm{o}}$ and light of wavelength $8000\mathop {\rm{A}}\limits^{\rm{o}}$ both produce a bright fringe at P
B
D
A
C
A small hollow vessel which has a small circular hole of radius $r$ in its base, is immersed in a tank of oil of density $\rho$ and surface tension $T$. The oil will penetrate into the vessel at a depth of
$\frac{2 T}{r \rho g}$
$\frac{T}{r \rho g}$
$\frac{4 T}{r \rho g}$
$$ \frac{2}{\operatorname{r} \rho g T} $$
Two-point charges of equal magnitude 0.01 C and opposite in sign are separated by 0.2 mm , forming an electric dipole. The electric dipole moment of the dipole is:
$2 \times 10^{-3} \mathrm{Cm}$ along the line joining the two charges and the direction of the dipole moment vector is from negative to positive 0.01 C
$4 \times 10^{-6} \mathrm{Cm}$ along the line joining the two charges and the direction of the dipole moment vector is from positive to negative 0.01 C
$2 \times 10^{-6} \mathrm{Cm}$ along the line joining the two charges and the direction of the dipole moment vector is from negative to positive 0.01 C
$2 \times 10^6 \mathrm{Cm}$ along the line joining the two charges and the direction of the dipole moment vector is from positive to negative 0.01 C
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