Assertion: The energy of charged particle moving in a uniform magnetic field does not change.
Reason: Work done by magnetic field on the charge is zero
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
A Ge specimen is doped with Al. The concentration of acceptor atoms is ∼ 1021 atoms/m3. Given that the intrinsic concentration of electron-hole pairs is 1019/m3, the concentration of the specimen is
1017/m3
1015/m3
104/m3
102/m3
In Young's double slit experiment, the distance between two slits is made three times then the fridge width will become
9 times
1/9 times
3 times
1/3 times
A laser beam is used for carrying out surgery because, it
is highly monochromatic
is highly coherent
is highly directional
can be sharply focussed
A coverging lens forms a real image I of an object on its principal axis. A rectangular slab of refractive index and thickness x is introduced between l and the lens, I will move
towards the lens ( μ - 1 ) x
towards the lens by x
away from the lens by (μ - 1 ) x
away from the lens by x
N1 atoms of a radioactive element emit N2 beta particles per second. The decay constant of the element is ( m s-1 )
N1/N2
N2/N1
N1 ( ln2 )
N2 ( ln2 )
Which of the following is matched wrongly?
Oil drop experiment → Millikan
Dual nature of light → de Broglie
Uncertainty principle → Heisenberg
None of these
The forbidden gap in the energy bands of sillicon is
2.6 eV
1.1 eV
0.1 eV
6 eV
B.
1.1 eV
The forbidden energy gap is defined as by the amount of energy that is needed to release an electron from its valence band to its conduction band. Electrons can not exist in this gap. They are either below it, and bound to an atom, or above it, and able to move freely.
The forbidden gap in the energy band of Si = 1.1 eV
When white light passes through a prism, the deviation is maximum for
violet light
green light
red light
yellow light
Which of the following gates correspond to the truth table given below?
A | B | Y |
0 | 0 | 1 |
0 | 1 | 0 |
1 | 0 | 0 |
1 | 1 | 0 |
NAND
OR
XOR
NOR