A astronomical telescope has objective and eyepiece of focal lengths 40 cm and 4 cm respectively. To view an object 200 cm away from the objective, the lenses must be separated by a distance
A
50.0 cm
B
54.0 cm
C
37.3 cm
D
46.0 cm
2
NEET 2016 Phase 1
MCQ (Single Correct Answer)
+4
-1
The angle of incidence for a ray of light at a refracting surface of a prism is 45o. The angle of prism is 60o. If the ray suffers minimum deviation through the prism, the angle of minimum deviation and refractive index of the material of the prism respectively, are
A
$${45^o};\sqrt 2 $$
B
$${30^o};{1 \over {\sqrt 2 }}$$
C
$${45^o};{1 \over {\sqrt 2 }}$$
D
$${30^o};\sqrt 2 $$
3
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
In an astronomical telescope in normal adjustment a straight black line of length L is drawn on inside part of objective lens. The eye-piece forms a real image of this line. The length of this image is $$I$$. The magnification of the telescope is
A
$${{L + I} \over {L - I}}$$
B
$${L \over I}$$
C
$${L \over I} + 1$$
D
$${L \over I} - 1$$
4
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
A beam of light consisting of red, green and blue colours is incifent on a right angled prism. The refractive index of the material of the prism for the above red, green and blue wavelengths are 1.39, 1.44 and 1.47 respectively.
The prism will
A
not separate the three colours at all
B
separate the red colour part from the green and blue colours
C
separate the blue colour part from the red and green colours
