The capacitance of a capacitor will decrease if we introduce a slab of:
(a) copper
(b) aluminium
(c) zinc
(d) None of these
(a) copper
(b) aluminium
(c) zinc
(d) None of these
(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
The capacitance of earth, viewed as a spherical conductor of radius 6408 km is:
(a) 1420 μF
(b) 712 μF
(c) 680 μF
(d) 540 μF
In which of the following forms is the energy stored in a capacitor?
(a) Charge
(b) Potential
(c) Capacitance
(d) Electric field
Choose the SI unit of electric potential energy :
(a) Joule
(b) Coulomb
(c) Newton per coulomb
(d) Erg
Minimum number of capacitor of 2μF each required to obtain a capacitance of 5μF will be:
(a) 4
(b) 3
(c) 5
(d) 6
Angular width of interference fringe depends on
(A) Distance Between Slit and Screen
(B) Ratio of the wavelength and Slit width
(C) Wavelength of light
(D) Width of Slit
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.
The phenomena which is not explained by Huygen’s construction of wavefront
(a) reflection
(b) diffraction
(c) refraction
(d) origin of spectra
Two wires of same length are shaped into a square and a circle. If they carry same current, the ratio of their magnetic moment-
a) 2:π
b)π:2
c) 4:π
d) π:4.
A wire in the form of a circular loop, of one turn carrying a current, produces magnetic induction B at the centre. If the same wire is looped into a coil of two turns and carries the same current, the new value of magnetic induction at the centre is-
a) B
b) 4B
c) 2B
d) 8B.
How does the fringe width alter, if the entire Young’s double slit experimental set up is completely immersed into water ?
I. Increases
II. Decreases
III. Remains same
IV. None of these
Two interfering beams have intensities in the ratio of 9:4. Then the ratio of maximum to minimum intensity in the interference pattern is
(A) 25:1
(B) 13:5
(C) 5:1
(D) 3:2