alleryStart learning →A material in air has sin C=0.4. Its refractive index is
- 2.5
- 0.4
- 4.0
- 1.4
Show answer and solution
Correct answer: A. 2.5
For a material bordering air, n = 1/sin C = 1/0.4 = 2.5.
ICSE Class 10 Ray Optics and Optical Instruments — practice questions — page 3
Explore 86 free Ray Optics and Optical Instruments questions in ICSE Class 10 Physics. Open each question or exercise to read its content, reference answers and available explanation.
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Showing questions 61–86 of 86.
A material in air has sin C=0.4. Its refractive index isRead the answer and worked solution →Glass-air critical angle is 40°. At incidence 39°, lightRead the answer and worked solution →At 80° incidence from air into glass, which remains possible?Read the answer and worked solution →Glass is moved from air into water. Its critical angle at the outside boundaryRead the answer and worked solution →Vacuum wavelengths are 100, 500 and 1000 nm. Which has highest frequency?Read the answer and worked solution →In vacuum, c=3×10^8 m/s. A 600 nm wave has frequencyRead the answer and worked solution →In vacuum, c=3×10^8 m/s and f=2×10^14 Hz. Wavelength and band?Read the answer and worked solution →Two vacuum wavelengths are 300 and 600 nm. Frequency ratio f300:f600?Read the answer and worked solution →At an interface, nonzero incidence equals refraction. The two indices areRead the answer and worked solution →Which sequence has increasing wavelength?Read the answer and worked solution →Glass has nred=1.50, nviolet=1.54. Which has the smaller critical angle in air?Read the answer and worked solution →X is denser by mass, but nX=1.2 and nY=1.5. Light is slower inRead the answer and worked solution →A prism ray has incidence 35° and emergence 55°. On reversing its path, incidence isRead the answer and worked solution →A glass-air ray meets the surface at 60° to it. C=40°. What occurs?Read the answer and worked solution →c=3×10^8, glass v=1.5×10^8 m/s. At 45° incidence to glass-air, the rayRead the answer and worked solution →Air view near normal: v=2×10^8, c=3×10^8 m/s; real depth 30 cm. Apparent depth?Read the answer and worked solution →Same real depth, near-normal air view: apparent 6 cm at n=4/3, 4 cm in X. Find nX.Read the answer and worked solution →At an interface sin i/sin r=1.5; speed in medium 1 is 2.4×10^8 m/s. Speed in 2?Read the answer and worked solution →Normal entry into a 30° prism in air, n=1.5. At its next face, sin emergence isRead the answer and worked solution →Glass n=1.5, sin i=0.8. Outside is air n=1 or water n=4/3. TIR occurs withRead the answer and worked solution →A water-air ray is 35° to the surface. Critical angle=48°. What follows?Read the answer and worked solution →Light: air λ=600 nm, c=3×10^8; glass speed=2×10^8 m/s, frequency unchanged. Glass λ?Read the answer and worked solution →Vacuum radiation f=10^15 Hz; c=3×10^8 m/s. Which wavelength and band fit?Read the answer and worked solution →In vacuum, infrared λ=1 μm and UV λ=0.25 μm. Which frequency is greater?Read the answer and worked solution →Normal entry: 30° prism in air, n=1.5. Given sin^-1(0.75)=48.6°. Deviation?Read the answer and worked solution →Prism A=60°, incidence 40°, deviation 30°. Reverse the path. New incidence?Read the answer and worked solution →
Worked practice questions
Glass-air critical angle is 40°. At incidence 39°, light
- Is totally internally reflected
- Is completely absorbed
- Partly refracts into air
- Travels along the interface
Show answer and solution
Correct answer: C. Partly refracts into air
Incidence below the critical angle allows partial transmission into air along with internal reflection.
At 80° incidence from air into glass, which remains possible?
- Transmission into the glass
- Refraction with no bending
- Complete absorption of light
- Total internal reflection
Show answer and solution
Correct answer: A. Transmission into the glass
Air-to-glass incidence is from rarer to denser material, so it allows transmission and cannot produce total internal reflection.
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