DAY 13 CIVILEZY CIVILWAR (PLANE TABLE,CONTOURING) (OCT 7)

What is the distance between point A and the 42 m contour, given AB = 10 m, RLs = 41.3 m & 43.8 m, and contour interval = 1 m?

• 3 m
• 2.8 m
• 3.5 m
• 2.6 m

Answer explanation

Linear interpolation between RL 41.3 and 43.8 places 42.0 at 2.8 m from A.

The fix of a plane table from three known points is good if

• Middle station is nearest
• Middle station is farthest
• Either right or left station is nearest
• None of these

Answer explanation

Greater included angles (middle farthest) improve resection accuracy.

The contour interval for a general topographical map with a scale of 1 cm = 100 m or more is typically:

• 0.5 m
• 1 m
• 2 m
• 3 m and above

Answer explanation

Small-scale topo maps use larger intervals (≥ 3 m) for clarity.

How will you test the plane table board to ensure that the upper surface is a perfect plane?

• Set up and level the plane table over a station
• Check with a straight edge in all directions
• If the bubble is not central, correct by packing under the board
• None of these

Answer explanation

A straightedge placed in multiple directions verifies planeness.

What is the length range of an alidade?

• 30 cm – 50 cm
• 50 cm – 60 cm
• 50 cm – 90 cm
• 70 cm – 100 cm

Answer explanation

Most alidades are manufactured in the 50–90 cm range.

What staff reading is required for setting a given grade?

• Change point
• Gradient
• Grade rod
• Stakes

Answer explanation

A grade rod provides the staff reading corresponding to the formation level.

Which method is used to establish grade stakes while the grade is uniform for a considerable distance?

• Setting out
• Radiating gradient
• Shooting in gradient
• Ranging gradient

Answer explanation

Shooting in gradient is used to set stakes along a uniform slope.

Which of the following is NOT a typical size of a plane table?

• Small: 50 cm × 40 cm × 1.5 cm
• Medium: 50 cm × 50 cm × 1.5 cm
• Large: 75 cm × 60 cm × 1.5 cm
• Extra Large: 100 cm × 80 cm × 2 cm

Answer explanation

Standard sizes usually go up to 75 × 60 cm; 100 × 80 × 2 cm is uncommon.

Which part of the plane table should be securely fastened to avoid issues during use?

• The vertical axis
• The butterfly nuts that clamp the legs to the clamping head
• The tripod legs
• The surface where the drawing is made

Answer explanation

Loose butterfly nuts cause wobble/shifts; clamping them prevents movement.

How are the vanes fixed in a plain alidade?

• Bolted
• Hinged
• Welded
• Screwed