CBSE Class 12 Optics — practice questions
33 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 Optics in the app →The critical angle for total internal reflection at a glass-air interface is $42^\circ$. The refractive index An object is placed $30\,\text{cm}$ in front of a concave mirror of focal length $20\,\text{cm}$. The image diTwo plane mirrors are inclined at an angle of $60^\circ$. The number of images of a point object placed betweeA convex mirror always forms an image of a real object that is:A point source of light is placed at the origin in an isotropic medium. The wavefronts associated with the ligWhen monochromatic light passes from vacuum into a medium of refractive index $\mu$:In a Young's double slit experiment, the slits are separated by $d = 0.5\,\text{mm}$ and the screen is $D = 1.In a two-slit interference pattern, dark fringes (destructive interference) occur where the path difference beIn a YDSE setup with slit separation $d$ and screen distance $D$, the wavelength of the light source is doubleFor two-source interference to produce a stable observable fringe pattern, the sources must be:Light of wavelength $500\,\text{nm}$ falls on a single slit of width $0.1\,\text{mm}$. The angular width of thThe angle of reflection is equal to the angle of:The incident ray, the reflected ray and the normal all lie in:Snell's law introduces a constant known as the:The refractive index for a pair of media is independent of the:If the refractive index is greater than one, the refracted ray bends:In total internal reflection, transmission of light is:In ordinary reflection, the reflected ray is always:The critical angle is the angle of incidence for which refraction is:The critical angle of water with respect to air is about:The refractive index of water is:The refractive index of diamond is:The critical angle of diamond is about:Crown glass has a refractive index of:The SI unit for the power of a lens is the:A lens of focal length one metre has a power of:The power of a converging lens is:A prescribed lens of power plus 2.5 D is a convex lens of focal length:A lens of power minus 4.0 D is a concave lens of focal length:In the visible spectrum, red light lies at the:Violet light has a wavelength of about:Dispersion happens because the refractive index differs with:Which colour travels fastest in a glass prism?