D45 MASTER THE DAY

What is the line joining the optical center of the objective to the intersection of crosshairs called?

• Axis of telescope
• Axis of bubble tube
• Line of collimation
• Vertical axis

Answer explanation

Line of collimation is the imaginary line connecting the optical center to the intersection of crosshairs.

Which part of the theodolite rotates around the vertical axis?

• Upper plate
• Lower plate
• Vertical circle
• Telescope

Answer explanation

The upper plate rotates around the vertical axis to measure horizontal angles.

What is the purpose of the diaphragm in theodolite?

• To adjust magnification
• To eliminate parallax
• To hold crosshairs
• To support vertical circle

Answer explanation

The diaphragm holds the crosshairs at the common focal plane.

Which reading method involves measuring an angle several times and averaging?

• Reiteration
• Repetition
• Direct
• Transit

Answer explanation

Repetition method increases accuracy by taking and averaging multiple angle measurements.

Which component ensures the vertical axis is truly vertical?

• Plumb bob
• Tripod
• Plate bubble
• Circular bubble

Answer explanation

The plate bubble is leveled to ensure the vertical axis is truly vertical.

What is the full form of DMD in area calculation?

• Double Meridian Distance
• Direct Meridian Distance
• Derived Mean Distance
• Deviation Meridian Distance

Answer explanation

DMD stands for Double Meridian Distance, used in coordinate-based area computation.

Which axis should be perpendicular to the vertical axis for accurate angle measurement?

• Axis of telescope
• Axis of bubble tube
• Trunnion axis
• Line of sight

Answer explanation

Trunnion axis must be perpendicular to vertical axis for correct measurement of angles.

Which error occurs due to unequal graduation spacing on the theodolite scale?

• Collimation error
• Index error
• Graduation error
• Instrumental error

Answer explanation

Graduation error occurs due to uneven divisions on the scale circle.

Which type of bubble is used in circular level of a theodolite?

• Box bubble
• Torpedo bubble
• Circular bubble
• Cylindrical bubble

Answer explanation

Circular bubble helps roughly level the instrument before fine adjustment.

Which is the most suitable curve for smooth entry and exit from circular curves?

• Compound curve
• Transition curve
• Reverse curve
• Deviation curve

Answer explanation

Transition curve ensures gradual change in curvature, reducing jerk during movement.