The magnifying power of telescope is high if the objective has a long focal length and the eye-piece has a short focal length
44) The magnifying power of telescope is high if
Answer is:
the objective has a long focal length and the eye-piece has a short focal length
Explanation:
Related Optics MCQ with Answers
Answer is:
a converging lens of focal length 100 cm
Explanation:
A lens of power + 2.0 D is placed in contact with another lens of power ? 1.0 D. The combination will behave like a converging lens of focal length 100 cm
Answer is:
10 s
Explanation:
Suppose W is the power of the lamp. Then amount of energy needed to print photo is E=2.5*W/4??602 Now suppose t is the required time when the lamp is kept at 1.5 m away. So we have E=W/4??1202t Equating energy for both we get t=10 s.
Answer is:
30 cm
Explanation:
n1/u +n2/v=(n2-n1)/r for first refraction by convex surface: u??, v=rn2/(n2-n1) for plane reflection: r is infinite,v'=-v for second refraction: 1.5/v' -1/v''=(1-1.5)/r 1/v''+1/v=1/f power=1/f
Answer is:
1.5
Explanation:
n1/u +n2/v=(n2-n1)/r for first refraction by convex surface: u??, v=rn2/(n2-n1) for plane reflection: r is infinite,v'=-v for second refraction: 1.5/v' -1/v''=(1-1.5)/r 1/v''+1/v=1/f power=1/f