1
WB JEE 2022
+1
-0.25

The human eye has an approximate angular resolution of $$\theta$$ = 5.8 $$\times$$ 10$$-$$4 rad and typical photo printer prints a minimum of 300 dpi (dots per inch, 1 inch = 2.54 cm). At what minimal distance d should a printed page be held so that one does not see the individual dots?

A
20.32 cm
B
29.50 cm
C
14.59 cm
D
6.85 cm
2
WB JEE 2021
+1
-0.25
A spherical convex surface of power 5 D separates object and image space of refractive indices 1.0 and $$4\over3$$ , respectively. The radius of curvature of the surface is
A
20 cm
B
1 cm
C
4 cm
D
5 cm
3
WB JEE 2021
+1
-0.25

The cross-section of a reflecting surface is represented by the equation x2 + y2 = R2 as shown in the figure. A ray travelling in the positive x-direction is directed toward positive y-direction after reflection from the surface at point M. The coordinate of the point M on the reflecting surface is
A
$$\left( {{R \over {\sqrt 2 }},{R \over {\sqrt 2 }}} \right)$$
B
$$\left( { - {R \over 2}, - {R \over 2}} \right)$$
C
$$\left( { - {R \over {\sqrt 2 }},{R \over {\sqrt 2 }}} \right)$$
D
$$\left( {{R \over {\sqrt 2 }}, - {R \over {\sqrt 2 }}} \right)$$
4
WB JEE 2020
+1
-0.25
A tennis ball hits the floor with a speed v at an angle $$\theta$$ with the normal to the floor. If the collision is inelastic and the coefficient of restitution is $$\varepsilon$$, what will be the angle of reflection?
A
$${\tan ^{ - 1}}\left( {{{\tan \theta } \over \varepsilon }} \right)$$
B
$${\sin ^{ - 1}}\left( {{{\sin \theta } \over \varepsilon }} \right)$$
C
$$\theta$$$$\varepsilon$$
D
$$\theta {{2\varepsilon } \over {\varepsilon + 1}}$$
WB JEE Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
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