Refracting Telescope: the Objective and the Eyepiece of a Refracting

question 25

Multiple Choice

Refracting telescope: The objective and the eyepiece of a refracting astronomical telescope have focal lengths of 320 cm and 4.0 cm, respectively. The telescope is used to view Neptune and the final image is set at infinity. The diameter of Neptune is 4.96 × 10⁷ m and the distance from the earth at the time of observation is 4.4 × 10¹² m. What is the angle (in mrad) subtended by the final telescopic image of Neptune?

• A) 0.90 mrad
• B) 1.1 mrad
• C) 1.3 mrad
• D) 1.5 mrad
• E) 1.7 mrad

---

Definitions:

Height Control Valve

A valve in air suspension systems that maintains or adjusts vehicle height by regulating air pressure.

Unsprung Weight

The weight of the components of a vehicle that are not supported by the suspension system, affecting handling and comfort.