D44 QUIZ OF THE DAY

What is the primary purpose of levelling in surveying?

• Measure angles
• Determine elevations
• Locate boundaries
• Mark property lines

Answer explanation

Levelling is used to determine the elevation of points with respect to a datum.

Which of the following is a non-reversible level?

• Wye level
• Cooke’s reversible level
• Cushing’s level
• Dumpy level

Answer explanation

Dumpy level is non-reversible as the telescope cannot rotate vertically.

What does a horizontal line represent in levelling?

• A line perpendicular to vertical axis
• A line parallel to plumb line
• A straight line on level surface
• A curved earth surface

Answer explanation

A horizontal line lies tangential to the level surface at a point and is straight.

Which part of the instrument removes parallax?

• Level tube
• Diaphragm
• Eyepiece
• Tripod

Answer explanation

The eyepiece is focused to remove parallax by aligning the image with cross hairs.

Which bench mark is assumed for local works?

• GTS
• Temporary
• Permanent
• Arbitrary

Answer explanation

Arbitrary bench mark is used for local work where no standard reference is available.

What is the equation for refraction correction?

• 0.0785 D²
• 0.0673 D²
• 1/7 x 0.0785 D²
• 6/7 x 0.0785 D²

Answer explanation

Refraction correction is approximately 1/7th of curvature correction.

Which level is known as self-aligning level?

• Auto level
• Dumpy level
• Tilting level
• Y level

Answer explanation

Auto level automatically adjusts the line of sight and is self-aligning.

In which method are spot levels used for contouring?

• Direct
• Radial
• Cross section
• Indirect

Answer explanation

Indirect method uses spot levels to interpolate contour lines.

What is the term for the vertical distance between two contours?

• Contour gradient
• Horizontal equivalent
• Contour interval
• Relief

Answer explanation

Contour interval is the vertical gap between adjacent contour lines.

Which levelling method is most accurate?

• Fly levelling
• Simple levelling
• Reciprocal levelling
• Barometric levelling

Answer explanation

Reciprocal levelling compensates for collimation, curvature and refraction errors.