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Hazara University, Examination: Midterm Time Allowed: 1 hour and 15 mins Max Marks : 120 (weightage Note: Attempt all Questions. Mobile as a calculator is not allowed. Rough Work is not allowed on Question paper. Exchange of things is not allowed. Q1. a) State Kepler’s three laws of planetary motion. Illustrate in each case their relevance to artificial satellites orbiting the earth. (10) b) Calculate the radius of a circular orbit for which the period is 1 day. (10) c) A satellite is orbiting in the equatorial plane with a period from perigee to perigee of 12 hours. Given that the eccentricity is 0.002, calculate the semi major axis. The earth’s equatorial radius is 6378.1414 km. (10) d) The orbit for an earth–orbiting satellite has an eccentricity of 0.15 and a semi major axis of 9000 km. Determine the periodic time. (10) Q2. a) Explain what is meant by ascending and descending nodes. Would you expect them to change with time? (10) b) With the aid of neat sketch, explain what is meant by each of the following (i) inclination (ii) argument of perigee (iii) mean anomaly (iv) True anomaly (v) Retrograde and Prograde orbit. (10) c) What is the fundamental unit of Universal Coordinated Time? Express the following times in (i) days and (ii) degrees. 0 h, 5 min, 24 s; 6 h, 35 min, 20 s; 7 h, 59 min, 5 s. (10) d) Determine the Julian days for the following days and times: midnight March 10, 1999; noon, February 23, 2000; 16:30 h. March 1, 2003; 3 P.M., July 4, 2010. (10) Department of IT Subject: Satellite Communications Program: BS Telecommunication Semester: 6 th (A&B)
