An air capacitor is charged with an amount of charge q and dipped into an oil tank. If the oil is pumped out, the electric field between the plates of capacitor will
(a) increase
(b) decrease
(c) remain the same
(d) becomes zero
(a) increase
(b) decrease
(c) remain the same
(d) becomes zero
(b) decrease
Three capacitors 3 μF, 6 μF and 6 μF are connected in series to a source of 120 volt. The potential difference across the 3 μF capacitor will be
(a) 40 volt
(b) 30 volt
(c) 40 volt
(d) 60 volt
Two capacitors of capacitance 6 µF and 4 µF are put in series across a 120 V battery. What is the potential difference across the 4 µF capacitor?
(a) 72 V
(b) 60 V
(c) 48 V
(d) zero
Equipotential surfaces at a great distance from a collection of charges whose total sum is not zero are approximately
(a) spheres
(b) planes
(c) paraboloids
(d) ellipsoids
In which of the following forms is the energy stored in a capacitor?
(a) Charge
(b) Potential
(c) Capacitance
(d) Electric field
A parallel plate capacitor is made by stacking n equally spaced plates connected alternately. If the capacitance between any two plates is C, then the resultant capacitance is
(a) C
(b) nC
(c) (n-1)C
(d) (n+1)C
The electric potential of earth is taken to be zero, because earth is a good
(a) insulator
(b) conductor
(c) semiconductor
(d) dielectric
A dielectric induces....... in an external electric field which decreases the net electric field.
(a) current
(b) dipole moment
(c) magnetic field
(d) polarisation
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
Two-point charges 2μC and 4μC are placed 2 cm apart. The ratio of the Coulomb’s force experienced by them is
(A) 1: 2
(B) 2: 1
(C) 1: 1
(D) 4: 1
In Young’s double-slit experiment, the phase difference between the light waves reaching the third bright fringe from the central fringe will be (λ=6000 Å)
(a) zero
(b)2
(c) 4
(d) 6
Huygens theory could not explain
a. Reflection of light
b. Photoelectric effect
c. Interference of light
d. Diffraction of light
What happens to the interference pattern, the two slits S1 and S2 in Young’s double slit experiment are illuminated by two independent but identical sources?
a. The intensity of the bright fringes doubled
b. The intensity of the bright fringes becomes four times
c. Two sets of interference fringes overlap
d. No interference pattern is observed.
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
Select the correct statements from the following
(i) inside a charged or neutral conductor, electrostatic field is zero.
(ii) the electrostatic field at the surface of the charged conductor must be tangential to the surface at any point.
(iii) there is no net charge at any point inside the conductor.
(A) (i) and (ii)
(B) i) and (iii)
(C) (ii) and (iii)
(D) (i), (ii), and (iii)