Home › CBSE Class 12 (Science) › Physics › Ray Optics and Optical Instruments › Tube length of an astronomical telescope in norm…
Tube length of an astronomical telescope in normal adjustment is
Afo + fe
Bfo - fe
Cfo x fe
Dfo / fe
Answer & Solution
Correct answer: A. fo + fe
The objective forms its image at its focus, which coincides with the eyepiece focus, so the lenses are fo + fe apart.
Related questions
A prismatic corner reflector turns incoming light back along its path using how many totalIn a wiper rain sensor, water drops do what to the infrared beam?Which device uses the critical angle to measure the refractive index of a substance?Which prism pair is commonly used to turn the view upright in binoculars?At the critical angle, the refracted ray travels in which direction?A swimmer looking up from below calm water sees the outside world compressed into a cone. Optical fibres carry signals over long distances by which principle?Diamond has a refractive index of about 2.42. Roughly what is its critical angle in air?