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MathsMediumNumerical2024 · 08 Apr Shift 1

Q87.If the range of f(θ) = sin4 θ+3 cos2 θ , θ ∈R is [α, β] , then the sum of the infinite G.P., whose first term is 64 and sin4 θ+cos2 θ the common ratio is α , is equal to________ β

What This Question Tests

This question involves finding the range of a trigonometric function by converting it to a quadratic in sin²θ or cos²θ and then using this range as the common ratio for an infinite geometric progression.

Concepts Tested

Trigonometric identitiesRange of functionsGeometric Progression sum

Formulas Used

sin^2θ + cos^2θ = 1

Sum of infinite G.P. = a / (1-r)

📚 NCERT Sections This Tests

9.17(A) Sin I¢C = 1.44/1.68 Which Gives I¢C = 59°. Total Internal Reflection

Physics Class 12 · Chapter 9

68% match

9.17 (a) sin i¢c = 1.44/1.68 which gives i¢c = 59°. Total internal reflection takes place when i > 59° or when r < rmax = 31°. Now, (sin i /sin r max max ) = 1.68 , which gives imax ~ 60°. Thus, all incident rays of angles in the range 0 < i < 60° will suffer total internal reflections in the pipe. (If the length of the pipe is finite, which it is in practice, there will be a lower limit on i determined by the ratio of the diameter to the length of the pipe.) (b) If there is no outer coating, i¢c = sin–1(1/1.68) = 36.5°. Now, i = 90° will have r = 36.5° and i¢ = 53.5° which is greater than i¢c. Thus, all incident rays (in the range 53.5° < i < 90°) will suffer total internal reflections.

9.21At What Angle Should A Ray Of Light Be Incident On The Face Of A Prism

Physics Class 12 · Chapter 9

67% match

9.21 At what angle should a ray of light be incident on the face of a prism of refracting angle 60° so that it just suffers total internal reflection at the other face? The refractive index of the material of the prism is 1.524.

9.4Figures 9.27(A) And (B) Show Refraction Of A Ray In Air Incident At 60°

Physics Class 12 · Chapter 9

66% match

9.4 Figures 9.27(a) and (b) show refraction of a ray in air incident at 60° with the normal to a glass-air and water-air interface, respectively. Predict the angle of refraction in glass when the angle of incidence in water is 45° with the normal to a water-glass interface [Fig. 9.27(c)]. FIGURE 9.27

📋 Question Details

Chapter
Trigonometric Functions & Equations
Topic
Range of trigonometric functions and Geometric Progression
Year
2024
Shift
08 Apr Shift 1
Q Number
Q87
Type
Numerical
NCERT Ref
Class 11 Mathematics Ch 3: Trigonometric Functions; Class 11 Mathematics Ch 9: Sequences and Series

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