The insulation property of air, breaks down at E=3x \(10^6\)V/m. The maximum charge that can be given to a sphere of radius 2.5 m is approximately
(A) 2x \(10^{-2}\)C
(B) 2x \(10^{-3}\)C
(C) 3x \(10^{-6}\)C
(D) 3x \(10^{-5}\)C
(A) 2x \(10^{-2}\)C
(B) 2x \(10^{-3}\)C
(C) 3x \(10^{-6}\)C
(D) 3x \(10^{-5}\)C
(B) 2x \(10^{-3}\)C
\(10^6\) electrons are taken out of a pith ball. The positive charges on the pith ball is
A. 1.6x \(10^{-13}\) C
B. 1.6x \(10^{-19}\) C
C. 1.6x \(10^{-25}\) C
D. none of these
what is the angle between an electric dipole moment and then electric field strength due to it on its equatorial line?
(A) \(0^\circ\)
(B) \(90^\circ\)
(C) \(180^\circ\)
(D) None of these
What is the angle between the electric dipole moment and electric field strength due to it on the axial line?
(A) \(0^\circ\)
(B) \(90^\circ\)
(C) \(180^\circ\)
(D) None of these
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%
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
When 2 × \(10^{11}\) electrons are removed from a neutral metal sphere, the charge on the sphere becomes:
(A) -16 nC
(B) 16 nC
(C) -32 nC
(D) 32nC
Electric flux emanating through a surface element placed in an electric field is
(A) 10 units
(B) 20 units
(C) 4 units
(D) 16 units
There is a uniform magnetic field directed perpendicular and into the plane of the paper. An irregular shaped conducting loop is slowly changing into a circular loop in the plane of the paper. Then,
(a) Current is induced in the loop in the anti-clockwise direction
(b) Current is induced in the loop in clockwise direction
(c) AC Current is induced in the loop
(d) No current is induced in the loop
The magnetic flux linked with a coil is given by an equation Φ = 5t² + 2t + 3. The induced e.m.f. in the coil at the third second will be
(A) 32 units
(B) 54 units
(C) 40 units
(D) 65 units
Which of the following is conserved when light waves interefere?
a. Energy
b.Phase
c. Intensity
d. Amplitude
In a double slit interference pattern, the first maxima for infrared light would be
(a) at the same place as the first maxima for green light
(b) closer to the centre than the first maxima for green light
(c) farther from the centre than the first maxima for green light
(d) infrared light does not produce an interference pattern
Which of the following is not a property of electric field lines?
(A) Field lines are closed and continuous curves without any breaks.
(B) Two field lines cannot cross each other.
(C) Field lines start at positive charges and end at negative charges.
(D) They do not form closed loops.
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
Wavefront is the locus of all points, where the particles of the medium vibrate with the same
(a) phase.
(b) amplitude.
(c) frequency.
(d) period.