- AEinstein’s photoelectric effect.
- BFrank-Hertz experiment.
- CDavisson and Germer experiment.
- DMillikan’s oil drop experiment.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
A metal wire of specific resistance 64
and length 198 cm has a resistance of 7 ohm, the radius of the wire will be
|
(a) 2.4 cm |
(b) 0.24 cm |
(c) 0.024 cm |
(d) 24 cm |
Two different coils have self-inductance
,
. The current in one coil is increased at a constant rate. The current in the second coil is also increased at the same rate. At a certain instant of time, the power given to the two coils is the same. At that time the current, the induced voltage and the energy stored in the first coil are
and
respectively. Corresponding values for the second coil at the same instant are
and
respectively. Then
|
(a) |
(b) |
(c) |
(d) a, b, c |
The 21 cm radio wave emitted by hydrogen in interstellar space is due to the interaction called the hyperfine interaction is atomic hydrogen. the energy of the emitted wave is nearly
|
(a) |
(b) 1 Joule |
(c) 7 |
(d) |
Eight dipoles of charges of magnitude e are placed inside a cube. The total electric flux coming out of the cube will be
|
(a) |
(b) |
(c) |
(d) Zero |
The resistivity of a potentiometer wire is 40 and its area of cross-section is 8
. If 0.2 amp current is flowing through the wire, the potential gradient will be
|
(a) |
(b) |
(c) 3.2 |
(d) 1 volt/m |
A small bar magnet A oscillates in a horizontal plane with a period T at a place where the angle of dip is 60o. When the same needle is made to oscillate in a vertical plane coinciding with the magnetic meridian, its period will be
|
(a) |
(b) T |
(c) |
(d) 2T |
A magnetic field
|
(a) Always exerts a force on a charged particle |
|
(b) Never exerts a force on a charged particle |
|
(c) Exerts a force, if the charged particle is moving across the magnetic field lines |
|
(d) Exerts a force, if the charged particle is moving along the magnetic field lines |
Which radiation in sunlight, causes heating effect
|
(a) Ultraviolet |
(b) Infrared |
(c) Visible light |
(d) All of these |