| 1 |
The fringe spacing in case of red light |
Increases
Decreases
Remains the same
None of these
|
| 2 |
In the phenomenon of interference, the bright and dark fringes are of |
Different width
Equal width
Dark fringes are thicker than bright
Nona of these
|
| 3 |
Fringe spacing ΔY is the distance between two adjacent bring fringes on the screen is |
ΔY = Lλ/d
ΔY = Ld/λ
ΔY = dλ/L
ΔY = Lλ/d m
|
| 4 |
If the bright fringe into be observed then we have relation |
Y = mLd/λ
Y = mλL/d
Y = λd/mL
Y = λL/md
|
| 5 |
When 'θ' is small then |
tan θ ≈ sin θ
cos θ ≈ sin θ
sin θ ≈ tan θ
None of these
|
| 6 |
Point out angle/angle at which the sin θ and tan θ have the same value |
2<sup>o</sup> and 8<sup>o</sup>
4<sup>o</sup> and 6<sup>o</sup>
2<sup>o</sup> and 4<sup>o</sup>
8<sup>o</sup> and 10<sup>o</sup>
|
| 7 |
If the path difference must be an integral multiple of wavelength |
sin θ = md/λ
d sin θ = mλ
d sin θ = m/λ
d sin θ = λ/m
|
| 8 |
Who devise the experimental arrangement in 1801 for studying interference effects of light |
Huygen
Young
Newton
None of these
|
| 9 |
The points on a Huygen's wave front which sends out secondary wavelets are also |
Source
Source of secondary wavelets
Coherent sources of light
None of these
|
| 10 |
Huygen's wave front which sends out secondary wavelets with a speed equal to |
Speed of propagation of the wave
Speed of propagation greater than wave
Speed of propagation less than the wave
None of these
|
| 11 |
The distance between two concentric wave fronts is |
A wave length
A half wavelength
Zero
None of these
|
| 12 |
The wave propagates in space by the motion of the |
Particles
Wavefronts
Wavelength
None of these
|
| 13 |
The light from the sun reaches to earth with wavefronts |
Spherical
Cylindrical
Plane
None of these
|
| 14 |
Can two lights of car can produce interference |
Yes
No
Partly produce interference
None of these
|
| 15 |
To observe the phenomenon of interference of light, the light should be |
Monochromatic
Phase coherence
Coherent sources
All of these
|
| 16 |
An oil surface floating on water surface exhibits beautiful colour patter, which is due to |
Reflection of light
Diffraction of light
Interference of light
None of these
|
| 17 |
The position of a new wavefront after a certain interval of time can be found by constructing a surface that is |
A tangent
A tangent envelope
Curved surface
None of these
|
| 18 |
Every point of a wavefront may be considered as a |
Source
Source of wavefront
Source of secondary wavefront
None of these
|
| 19 |
A plane wavefront is that which has source |
Nearest
Distant
Near
None of these
|
| 20 |
A spherical wavefront is that which has |
A source
A point source
An extended source
None of these
|
| 21 |
A line normal to the wave front is called |
A beam of light
A ray of light
Both
None of these
|
| 22 |
Wave front is the locus or all points in vibration are in the same |
Frequency
Phase
Wavelength
All of these
|
| 23 |
Who confirm the wave theory of light ? |
Newton
Michelson
Newton
Thomos Young
|
| 24 |
The idea of light as wave produced by |
Huygen
Newton
Thomos Young
Michelson
|
| 25 |
Who gave the idea of light as wave ? |
Newton
Huygen
Thomos Young
Bragg
|
| 26 |
Light is a type of energy which produces sensation of |
Sound
Feeling
Vision
None of these
|
| 27 |
In a semiconductor,the mobility of holes is |
Greater then electrons
Less than electrons
Equal to electrons
None
|
| 28 |
N-type crystal is |
Neutral
Positively charged
Negative charged
None of these
|
| 29 |
The critical temperature for mercury is |
1.18 K
4.2 K
3.72 K
7.2 K
|
| 30 |
Arsenic antimony or phosphorus are impurities of |
p-type
n-type
May be p-type or n-type
None of these
|
| 31 |
In n-type substances the minority carriers are |
Holes
Electrons
Neutrons
None
|
| 32 |
A substance which have empty conduction band is called |
Conductor
Insulator
Semiconductor
None of these
|
| 33 |
The electrons in the outermost shell of an atom are called |
Valence electrons
Tightly bound electrons
Free electrons
None of these
|
| 34 |
Young's modulus for copper is |
70 x 10 Nm<sup>-2</sup>
91 x 10 Nm<sup>-2</sup>
110 Nm<sup>-2</sup>
None of these
|
| 35 |
The units of modulus of elasticity are same as that of |
Stress
Strain
Force
None
|
| 36 |
The ratio of applied stress to volumetric strain is called |
shear modulus
Young's modulus
Bulk modulus
None of these
|
| 37 |
The measure of deformation of a solid when stress is applied to it is called |
Strain
Stress
Force
None of these
|
| 38 |
When a strength changes the length of a body,it is called |
Tensile stress
Shear stress
Compressional stress
|
| 39 |
The whole structure obtained by the repetition of unit cell is known as |
Unit cell
Crystal lattice
Ore
All of these
|
| 40 |
Polythene,polystyrene and nylon are example of |
Polymeric solids
Crystalline solids
Glassy solids
|