Understudies can discover the chapter astute vital questions for course 12th Physics within the table underneath. These imperative questions incorporate questions that are regularly inquired in a long time. Moreover, arrangements are to give for these questions, with extraordinary accentuation on ease-of-study. Tap on the joins underneath to begin investigating.
Below we posted all the Case Study Questions & Answers for Class 12 Physics all Chapters –
CBSE Class 12 Case Study Question for Physics
Case Study 01:
(12)
To a distant observer, the light appears to be coming from somewhere below the ground. The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object.
Such inverted images of distant tall objects cause an optical illusion to the observer. This phenomenon is called mirage. This type of mirage is especially common in hot deserts.
Based on the above facts, answer the following questions:
(a) Which of the following phenomena is prominently involved in the formation of mirage in deserts?
(i) Refraction, Total internal Reflection
(ii) Dispersion and Refraction
(iii) Dispersion and scattering of light
(iv) Total internal Reflection and diffraction.
Ans: (i) Refraction, Total internal reflection
(b) A diver at a depth 12 m inside water (aμω= 4/3) sees the sky in a cone of semi-vertical angle
(i) sin-1 4/3
(ii) tan-1 4/3
(iii) sin-1 3/4
(iv) 90°
Ans: (iii) sin-1(3/4)
aμω = 1/sin C
=>sin C = 1/aμω
=> sin-1 (1/aμω)
(c) In an optical fibre, if n1 and n2 are the refractive indices of the core and cladding, then which among the following, would be a correct equation?
(i) n1< n2
(ii) n1 = n2
(iii) n1<<2
(iv) n1> n2
Ans: (iv) n1> n2
The refractive index of the core should be greater than the refractive index of the cladding.
(d) A diamond is immersed in such a liquid which has its refractive index with respect to air as greater than the refractive index of water with respect to air. Then the critical angle of diamond-liquid interface as compared to critical angle of diamond -water interface will
(i) depend on the nature of the liquid only
(ii) decrease
(iii) remain the same
(iv) increase.
Ans: (iv) increases
Iμd= 1/sin C = μd/μ1 ,ωμd = 1/sin C’ = μd/μω
μ1>μω
Thus C>C’
(e) The following figure shows a cross-section of a ‘light pipe’ made of a glass fiber of refractive index 1.68. The outer covering of the pipe is made of a material of refractive index 1.44. What is the range of the angles of the incident rays with the axis of the pipe for the following phenomena to occur.
(i) 0 << 90°
(ii) 0 << 60°
(iii) 0 << 45°
(iv) 0<< 30°
Ans: (ii) 0 << 60° , 1μ2 = 1/sin C’
sin C’ = 1.44/1.68 = 0.8571
=> C’ = 59°
Total internal reflection will occur if the angle i’ >i’c , i.e. , if i’ > 59° or when r <rmax’ where rmax = 90° – 59° = 31°. Using Snell’s law,
sinimax/sin rmax = 1.68
Or
Sin imax = 1.68 × sin rmax
= 1.68 × sin 31° = 1.68 × 0.5150 = 0.8662
∴imax = 60°
Thus all incident rays which make angles in the range 0 < i < 60° with the axis of the pipe will suffer total internal reflections in the pipe.
Chapter-1: Electric Charges And Fields
Chapter-2: Electrostatic Potential And Capacitance
Chapter-3: Current Electricity
Chapter-4: Moving Charges And Magnetism
Chapter -5: Magnetism & Matter
Chapter – 6 Electromagnetic Induction
Chapter – 7 Alternating Current
Chapter – 8 Electromagnetic Waves
Chapter – 9 Ray Optics And Optical Instruments
Chapter – 10 Wave Optics
Chapter 11 – Dual Nature Of Radiation And Matter
Chapter 12 – Atoms
Chapter 13 – Nuclei
Chapter 14 – Semiconductor Electronics: Materials, Devices And Simple Circuits
Key questions for 12th review Biology are outlined agreeing to the CBSE NCERT program. All address sorts are accessible within the PDF, from one-word to one-line answers, brief reply sorts to five point long reply sorts. Hence, understudies can plan for exams and indeed clarify their concepts through them. On the off chance that they refer to these questions, it’ll get ready their minds to pick up a competitive advantage. Understudies will gotten to be commonplace with question patterns and the sorts of questions that will show up on exams.