Light reflection and refraction Worksheet-2
A. 1.33 B. 0.75 C. 0.707 D. 1.5
A. /2 B.
C. 1/ D. None of these
A. B. /2 C. 2/ D. 2
A. 10 cm B. 15 cm C. 5 cm D. 26.67 cm
A. real and inverted, v = 30 cm, h_{2} = –4.0 cm
B. Virtual and inverted, v = 30 cm, h_{2} = 4.0 cm
C. real and inverted, v = 15 cm, h_{2} = 4.0 cm
D. None of these
Answer Key:
Here, speed of light in water, u = 2.25 × 10^{8} m/s
Speed of light in vacuum, c = 3 × 10^{8} m/s, refractive index n = ?
From
Here, angle of incidence i = 45° and angle of refraction, r = 30°
refractive index of medium 2 w.r.t. medium ^{1}n_{2} = ?
According to Snell’s law,
Here, ^{2}n_{1} = ?
As
Here, real depth of pond x = 20 cm
Refractive index of water
Apparent depth, y = ?
As
Given object size, h_{1} = 2.0 cm
Focal length of convex lens, f = 10 cm
Object distance, u = –15 cm
Image distance, v = ?
Image size h_{2} = ?
According to Lens formula
∴
v = 30 cm
As v is positive, the image formed is on the right side of the lens. It must be real and inverted. Now
Linear magnification,
∴
h_{2} = –4.0 cm
And m = –2
Negative sign of m and h_{2} show that the image is inverted.
Thus a real, inverted image enlarged 2 times (i.e. 4.0 cm tall) is formed at a distance of 30 cm on the right side of the lens.