Related Questions

What type of lens is used in a magnifying glass
A Concave
B Plano-concave
C Convex
D None of the above
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
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
In distributing milk at a summer camp it is found that a quart of milk will fill either 3 large glass tumblers. How many small glass tumblers can be filled with one large glass tumbler ?
A 11/5
B 7/5
C 5/3
D 7/3
In distributing milk at a summer camp it is found that a quart of milk will fill either 3 large glass tumblers or 5 small lass tumblers. How many small glass tumblers can be filled with one large glass tumbler?
A 11/5
B 7/5
C 5/3
D 7/3
A glass when full of milk, weighs 1 kg. It weighs 0.75 kg when the glass is half full. What is weight of the empty glass?
A 0.25 kg
B 0.35 kg
C 0.40 kg
D 0.50 kg
The major constituent of laminate of safety glass, which holds the broken glass, pieces in their places during accident (and thus minimises the danger from flying glass fragments) is
A Polyvinyl alcohol
B Polyvinyl acetale
C Polyvinyl butyral
D PVC
Lens is made up of which glass
A Ordinary glass
B Pyrex glass
C Flint glass
D Cobalt glass
Type of glass used in optical work is the __________ glass.
A Soda-lime
B Fibre
C Lead
D Borosilicate
The type of high refractive index glass used in optical instruments is __________ glass.
A Pyrex
B Flint
C Crookes
D None of these

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