MCQ 11 Mark
In a white light spectrum produced by dispersion of light through a prism the ray that is deviated least is :
- Ayellow
- Bblue
- Cgreen
- ✓red
Answer
View full question & answer→Correct option: D.
red
D
Questions
M.C.Q (1 Marks)
Take a timed test
43 questions · auto-graded multiple-choice test.
MCQ 21 Mark
The resolving power of a telescope can be increased by increasing :
- AWavelength of light
- ✓Diameter of objective
- CLength of the tube
- DFocal length of eyepiece
Answer
View full question & answer→Correct option: B.
Diameter of objective
B
MCQ 31 Mark
A biconvex lens of glass having refractive index 1.47 is immersed in a liquid. It becomes invisible and behaves as a plane glass plate. The refractive index of the liquid is :
- ✓1.47
- B1.62
- C1.33
- D1.51
Answer
View full question & answer→Correct option: A.
1.47
A
MCQ 41 Mark
The colour of sky is blue due to :
- Ainterference
- ✓scattering
- Cdiffraction
- Dpolarisation
Answer
View full question & answer→Correct option: B.
scattering
B
MCQ 51 Mark
Image formed in compound microscope is :
- Areal and erect
- ✓real and inverted
- Cvirtual and inverted
- Dvirtual and erect
Answer
View full question & answer→Correct option: B.
real and inverted
B
MCQ 61 Mark
The nature of electron beams moving with uniform velocity in the same direction will be :
- Aconverging
- ✓diverging
- Cparallel
- Dnone of these
Answer
View full question & answer→Correct option: B.
diverging
B
MCQ 71 Mark
Which causes the formation of rainbow ?
- ADiffraction
- BScattering
- CRefraction
- ✓Dispersion
Answer
View full question & answer→Correct option: D.
Dispersion
D
MCQ 81 Mark
Powers of two lenses kept in contact, are $P_{1}$ and $P_{2}.$ The power of equivalent lens will be :
- A$\frac{P_{1}}{P_{2}}$
- B$\frac{P_{2}}{P_{1}}$
- C$P_{1}\times P_{2}$
- ✓$P_{1}+P_{2}$
Answer
View full question & answer→Correct option: D.
$P_{1}+P_{2}$
D
MCQ 91 Mark
Image of any object formed at the retina of human eye is :
- ✓real and inverted
- Breal and erect
- Cvirtual and erect
- Dvirtual and inverted
Answer
View full question & answer→Correct option: A.
real and inverted
A
MCQ 101 Mark
Convex lens is used in :
- Ashort-sightedness
- ✓long-sightedness
- Cpresbyopia
- Dastigmatism
Answer
View full question & answer→Correct option: B.
long-sightedness
B
MCQ 111 Mark
A large virtual image of object is formed by :
- ✓concave mirror
- Bconvex mirror
- Cplane mirror
- Dconcave lens
Answer
View full question & answer→Correct option: A.
concave mirror
A
MCQ 121 Mark
Optical path is equal to :
- ✓Refractive index $\times$ path-length
- BRefractive index/path-length
- CPath-length/refractive index
- DRefractive index $\times \frac{\text { path-length }}{2}$
Answer
View full question & answer→Correct option: A.
Refractive index $\times$ path-length
A
MCQ 131 Mark
Which relation is correct for the power of compound microscope ?
- ✓$M=-\frac{L}{f_{0}}(1+\frac{D}{f_{e}})$
- B$M=-\frac{f_{0}}{L}(1+\frac{D}{f_{e}})$
- C$M=(1+\frac{D}{f_{e}})$
- D$M=(1-\frac{D}{f_{e}})$
Answer
View full question & answer→Correct option: A.
$M=-\frac{L}{f_{0}}(1+\frac{D}{f_{e}})$
A
MCQ 141 Mark
The power of convex lens of focal length 20 cm in dioptre is :
- A4
- ✓5
- C3
- D2
Answer
View full question & answer→Correct option: B.
5
B
MCQ 151 Mark
The velocity of light is maximum is :
- AAir
- BGlass
- CWater
- ✓Vacuum
Answer
View full question & answer→Correct option: D.
Vacuum
D
MCQ 161 Mark
Refractive index of diamond Is :
- A1
- B1.5
- ✓2.42
- D4.14
Answer
View full question & answer→Correct option: C.
2.42
C
MCQ 171 Mark
A Convex lens $(n=1.5)$ is immersed in water $(n=1.33)$, then it will behave as a :
- ✓Converging lens
- BDiverging lens
- CPrism
- DConcave mirror
Answer
View full question & answer→Correct option: A.
Converging lens
A
MCQ 181 Mark
Light owes its colour to its :
- AFrequency
- BVelocity
- ✓Phase
- DAmplitude
Answer
View full question & answer→Correct option: C.
Phase
C
MCQ 191 Mark
Cylindrical lenses are used to correct the eye defect called :
- AMyopia
- BHypermetropia
- ✓Astigmatism
- DPresbyopia
Answer
View full question & answer→Correct option: C.
Astigmatism
C
MCQ 201 Mark
The magnifying power of an astronomical telescope in the position of normal adjustment is given by :
- A$f_{o}+f_{e}$
- B$f_{o}\times f_{e}$
- ✓$f_{o}/f_{e}$
- D$f_{e}/f_{o}$
Answer
View full question & answer→Correct option: C.
$f_{o}/f_{e}$
C
MCQ 211 Mark
Which one of the following has maximum refractive index ?
- AGlass
- BWater
- CIron
- ✓Diamond
Answer
View full question & answer→Correct option: D.
Diamond
D
MCQ 221 Mark
The solar spectrums is :
- AContinuous
- ✓Line spectrum
- CSpectrum of black lines
- DSpectrum of black bonds
Answer
View full question & answer→Correct option: B.
Line spectrum
B
MCQ 231 Mark
Two lenses of power $-15D$ and $+5D$ when are in contact then the focal length of the combination is :
- A$-20$ cm
- ✓$-10$ cm
- C$+10$ cm
- D$+20$ cm
Answer
View full question & answer→Correct option: B.
$-10$ cm
B
MCQ 241 Mark
A thin lens is made up of a material of refractive index $\mu=1.51$. It is dipped into the water $(\mu=1.33)$. This lens will behave :
- ✓as a converging lens
- Bas a diverging lens
- Cas a rectangular glass slab
- Das a prism
Answer
View full question & answer→Correct option: A.
as a converging lens
A
MCQ 251 Mark
A convex lens is dipped in a liquid, whose refractive index is equal to refractive index of material of lens. Then its focal length will :
- ABecome zero
- ✓Become infinite
- CDecrease
- DIncrease
Answer
View full question & answer→Correct option: B.
Become infinite
B
MCQ 261 Mark
Critical angle for light moving in from medium I to medium II is $\theta$. The speed of light in medium I is v. Then speed in medium II is :
- A$v(1-\cos \theta)$
- ✓$\frac{v}{\sin \theta}$
- C$\frac{v}{\cos \theta}$
- D$v (1 \sin 0)$
Answer
View full question & answer→Correct option: B.
$\frac{v}{\sin \theta}$
B
MCQ 271 Mark
The image formed by objective lens of a compound microscope is :
- AVirtual and diminished
- BReal and diminished
- ✓Real and large
- DVirtual and large
Answer
View full question & answer→Correct option: C.
Real and large
C
MCQ 281 Mark
A magnifying glass is to be used at the fixed object distance of 1 inch. If it is to produce on erect image 5 items magnified, its focal length should be :
- A0.2"
- B0.8"
- ✓1.25"
- D5"
Answer
View full question & answer→Correct option: C.
1.25"
C
MCQ 291 Mark
To remove hyper-metropia lens used is :
- ✓Convex
- BConcave
- CCylindrical
- DPlano-Convex
Answer
View full question & answer→Correct option: A.
Convex
A
MCQ 301 Mark
A shortsighted person uses for clear vision :
- Aconvex lens
- ✓concave lens
- Ccylindrical lens
- Dbifocal length
Answer
View full question & answer→Correct option: B.
concave lens
B
MCQ 311 Mark
The angle of minimum deviation for thin prism of refractive index $\mu$ is :
- A$(1-\mu) A$
- ✓$(\mu-1) A$
- C$(\mu+1) A$
- D$(\mu+1) A^{2}$
Answer
View full question & answer→Correct option: B.
$(\mu-1) A$
B
MCQ 321 Mark
The critical angle of light passing from glass to air is minimum for :
- ARed colour
- BGreen colour
- CYellow colour
- ✓Violet colour
Answer
View full question & answer→Correct option: D.
Violet colour
D
MCQ 331 Mark
The focal length of a lens $(n=1.5)$ in air is 20 cm. Its focal length in medium of refractive index 1.5 is :
- A20 cm
- B40 cm
- C10 cm
- ✓$\infty$
Answer
View full question & answer→Correct option: D.
$\infty$
D
MCQ 341 Mark
When the length of a microscope tube is increased, its magnifying power :
- ✓increases
- Bdecreases
- Cbecomes zero
- Dremains unchanged
Answer
View full question & answer→Correct option: A.
increases
(A) increases
[Hint : $M=-\left(\frac{L}{f_o}\right)\left(1+\frac{D}{f_e}\right)$
when final image is formed at least distance of distinct vision
$\Rightarrow \quad M=-\left(\frac{L}{f_o}\right)\left(\frac{D}{f_e}\right)$when final image is formed at infinity.
where $\quad L =$ length of microscope
$\Rightarrow \quad M \propto L$
Hence on increasing the length of microscope its magnifying power increases.
[Hint : $M=-\left(\frac{L}{f_o}\right)\left(1+\frac{D}{f_e}\right)$
when final image is formed at least distance of distinct vision
$\Rightarrow \quad M=-\left(\frac{L}{f_o}\right)\left(\frac{D}{f_e}\right)$when final image is formed at infinity.
where $\quad L =$ length of microscope
$\Rightarrow \quad M \propto L$
Hence on increasing the length of microscope its magnifying power increases.
MCQ 351 Mark
The optical fibre works on the principle of :
- Ascattering
- Brefraction
- Cdispersion
- ✓total internal reflection of light
Answer
View full question & answer→Correct option: D.
total internal reflection of light
D
MCQ 361 Mark
How many images are formed by the lens shown in adjacent figure if an object is kept on its axis ?
- A1
- ✓2
- C3
- D7
Answer
View full question & answer→Correct option: B.
2
B
MCQ 371 Mark
When two converging lens of same focal length $f$ are placed in contact then the focal length of the combination is :
- A$f$
- B2$f$
- ✓$f/2$
- D3$f$
Answer
View full question & answer→Correct option: C.
$f/2$
C
MCQ 381 Mark
A biconvex lens $(n=1.5)$ has equal radius of curvature each of 20 cm. The power of the lens is :
- ✓5 D
- B10 D
- C2.5 D
- D20 D
Answer
View full question & answer→Correct option: A.
5 D
A
MCQ 391 Mark
S.I. unit of power of a lens is :
- Ajoule
- ✓diopter
- Ccandela
- Dwatt
Answer
View full question & answer→Correct option: B.
diopter
B
MCQ 401 Mark
In angle of prism and angle of minimum deviation each is A then the refractive index of the material of the prism will be :
- A$2 \sin (A/2)$
- ✓$2 \cos (A/2)$
- C$2 \tan (A/2)$
- D$2 \cot (A/2)$
Answer
View full question & answer→Correct option: B.
$2 \cos (A/2)$
MCQ 411 Mark
Two thin lenses of $+2D$ and $-4D$ power are kept in contact. Focal length of the combination is :
- A$+50$ m
- ✓$-50$ cm
- C$-25$ cm
- D$+25$ cm
Answer
View full question & answer→Correct option: B.
$-50$ cm
B
MCQ 421 Mark
When a lens is dipped into the water its focal length :
- ✓increases
- Bdecreases
- Cremains the same
- Dnone of these
Answer
View full question & answer→Correct option: A.
increases
A
MCQ 431 Mark
Out of the following which has its unit as diopter ?
- AFocus of the lens
- BFocal length of the lens
- ✓Power of the lens
- DMagnifying power of the lens
Answer
View full question & answer→Correct option: C.
Power of the lens
C