7-18.If station A and points B and C arein a straight line with station Abetween points B and C, what is thedistance between points B and C?1.640.5 ft2.641.5 ft3.1,095.0 ft4.1,096.0 ft7-19.What is the difference in elevationbetween points B and C?1.56.7 ft2.46.3 ft3.30.6 ft4.16.5 ft7-20.Stadia tables use a constant stadiadistance of1.50 ft2.100 ft3.101 ft4.200 ft7-21.Unequal refraction caused by thesun’s rays will have what effect onyour data?1.Cause longer distances thanactual to be read2.Cause shorter distances thanactual to be read3.Cause reversed vertical anglesto be read4.Cuuse smaller vertical anglesthan actual to be read7-22.How do you compensate forrefraction?1.By ignoring the instrumentconstant2.By taking all readings at twodifferent times of the day3.By shading the instrument4.By using the refractioncompensation formula7-23.The stadia circle providesconversion factors that are usedwith the stadia interval todetermine vertical and horizontaldistances.1.True2.False7-24.How is the arc reading of amultiplier scale used incomputations?1.Multiplied by the rod interceptto obtain the stadia distance2.Subtracted from the stadiadistance3.Added to the rod intercept andthen multiplied by the stadiaconstant4.Multiplied by the stadiainterval to obtain thehorizontal distance7-25.The subtraction scale gives apercentage reading that is used toreduce your stadia distances toobtain the actual distances.1.True2.False7-26.You are using a transit with amultiplier stadia arc. You have a93 reading on the horizontal stadiaarc with a depressed verticalangle. The rod intercept is 5.63.What is the horizontal distance?1.506.7 ft2.523.6 ft3.563.0 ft4.602.4 ft7-27.The elevation of station A is325.5 ft and the HI is 329.7 ft.You are sighted on point B. Youhave a -7 reading on the verticalstadia arc, a rod reading of 4.2,and a rod intercept of 5.1. Whatis the elevation of point B?1.289.8 ft2.318.8 ft3.361.2 ft4.372.9 ft47