Related Questions

The scale of a tilted photograph of focal length f, taken from an altitude H, along the plate parallel through plumb point, is
A $$\frac{{\text{f}}}{{{\text{H}}\sec \theta }}$$
B $$\frac{{{\text{f}}\sec \theta }}{{\text{H}}}$$
C $$\frac{{\text{f}}}{{\text{H}}}$$
D $$\frac{{\text{f}}}{{{\text{H}}\cos \frac{1}{2}\theta }}$$
একটি দ্বি-উত্তল অভিসারি লেন্সের প্রত্যেক পৃষ্ঠের বক্রতার ব্যাসার্ধ 30cm এবং গ্লাসের প্রতিসরাঙ্ক 1.50। লেন্সটির ফোকাস দৈর্ঘ্য কত হবে? (The radius of curvatures of both surfaces of a double convex lens are 30cm each and refractive index of glass is 1.50. What will be focal length of the lens?)
A 15 cm
B 30 cm
C 45 cm
D 60 cm
The product of the distances of plumb point and horizon point of a vertical photograph from its principal point, is
A f2
B 2f2
C 3f2
D $$\frac{1}{2}$$f
In the following sentence the word principal' occurs three times "The principal (1) aim of the principal (2) of the college was to help build new roads to link the area's principal (3)schools" Indicate the use(s) in which the meaning of the word “Principal is ‘chief or main',
A Use (1)
B Use(2)
C Use (3)
D Both (1) & (3)
Find the power of a convex lens if the image formed is at a distance of 25 cm from the lens when the object is placed on the other side of the lens at 12 cm from the optical centre?
A -4.33 diopters
B 12.33 diopters
C -12.33 diopters
D 4.33 diopters
________ helps the eye to adjust the focal length of the lens.
A Lens
B Ciliary body
C Retina
D Entire eye ball
The scale of a tilted photograph of focal length f taken from an altitude H, along the plate parallel through principal point is
A $$\frac{{\text{f}}}{{{\text{H}}\sec \theta }}$$
B $$\frac{{{\text{f}}\sec \theta }}{{\text{H}}}$$
C $$\frac{{\text{f}}}{{\text{H}}}$$
D $$\frac{{\text{f}}}{{{\text{H}}\cos \frac{1}{2}\theta }}$$
The point on the photograph where bisector between the vertical line through optical centre of the camera lens and the plate perpendicular meets, is known as
A Principal point
B Isocenter
C Plumb point
D Perspective centre
The point where a vertical line through the optical centre of the camera lens intersects the ground, is known as
A Ground principal point
B Ground plumb point
C Iso-centre
D Perspective centre
The alignment of a cross joint along the plumb line is
A Bed block
B Perpend
C Lintel
D Vertical line

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