The electric potential of earth is taken as:
(a) zero
(b) infinity
(c) unity
(d) None of these
(a) zero
(b) infinity
(c) unity
(d) None of these
(a) zero
The capacitance of a capacitor will decrease if we introduce a slab of:
(a) copper
(b) aluminium
(c) zinc
(d) None of these
The electric potential due to point charge 3 nC at distance of 9 cm is
(a) 270 v
(b) 3 v
(c) 300 v
(d) 30 v
Choose the SI unit of electric potential energy :
(a) Joule
(b) Coulomb
(c) Newton per coulomb
(d) Erg
The electric potential of earth is taken to be zero, because earth is a good
(a) insulator
(b) conductor
(c) semiconductor
(d) dielectric
Why are electric field lines perpendicular at a point on an equipotential surface of a conductor ?
If the width of the slit in single slit diffraction experiment is doubled, then the central maximum of diffraction pattern becomes:
(A) broader and brighter
(B) broader and fainter
(C) sharper and fainter
(D) sharper and brighter
Wave theory of light cannot explain the phenomena of
1. Polarisation 2. Diffraction 3. Interference 4. Crompton effect 5. Photoelectric effect
(A) 3, 4
(C) 1 ,2
(B) 1, 4, 5
(D) 4 ,5
In Young’s double slit experiment, the central point on the screen is:
(a) bright
(b) dark
(c) first bright and later dark
(d) first dark and later bright
An AC voltage source of variable angular frequency ω and fixed amplitude V connected in series with a capacitance C and an electric bulb of resistance R (inductance zero). When ω is increased
(a) The bulb glows dimmer
(b) The bulb glows brighter
(c) Net impedance of circuit is unchanged
(d) Total impedance of the circuit increases
Minimum number of capacitor of 2μF each required to obtain a capacitance of 5μF will be:
(a) 4
(b) 3
(c) 5
(d) 6
Two point charges, \(q_1\) = 10 × \(10^{-8}\)C, \(q_2\) = -2 × \(10^{-8}\)C are seperated by a distance of 60 cm in air what is the electrostatic potential energy of the system.
1) 3 joule
2) -3 joule
3) -3 x\(10^{-5}\) joule
4) 3 x\(10^{-5}\) joule
A square loop of side l , resistance R is placed in a uniform magnetic field B acting normally to the plane of the loop. If we attempt to pull it out of the field with a constant velocity v , then the power needed is
(a) BRlv
(b) B²l²v²/R
(c) B l²v²/ R
(d) Blv/R