An erect object is 50 cm from a concave mirror of radius 60 cm. In Situation 24.
ID: 1610346 • Letter: A
Question
An erect object is 50 cm from a concave mirror of radius 60 cm. In Situation 24.1, the character of the image is: A) virtual and erect B) real and inverted C) indeterminate D) virtual and inverted E) real and erect In Situation 24.1, the distance of the image from the mirror, in cm, is closest to: A) 75 B) 35 C) 60 D) 120 E) 19 In Situation 24.1, the lateral magnification of the image is closest to: A) -0.7 B) +1.5 C) -1.5 D) +0.4 E) +0.7 In Situation 24.1, the object is moved to a new position, such that the new lateral magnification is +2.5. The new object distance, in cm, is closest to: A)18 B) 24 C) 30 D) 36 E) 42Explanation / Answer
f = R/2 = 30 cm
object distance, p = 50 cm
Applying mirror equation,
1/f = 1/p + 1/q
1/30 = 1/50 + 1/q
q = 75 cm
m = - q / p = - 1.5
q > 0 so real image
m < 0 so inverted.
18. (B)
19. (A) 75 cm
20. m = - 1.5 Ans(C)
21. m = -q / p = 2.5
q = - 2.5p
1/30 = 1/p + 1/q = 1/p - 1/2.5p =0.6 / p
p = 18 cm
Ans(A)