(43) Correct answer: Option (2) 250 ft/mi

Steps of the calculation

Slop (gradient) = Vertical distance/Horizontal distance

Also known as rise (vertical distance) and run (Horizontal distance)

Since contour interval is = 100m

Vertical distance = Height of the higher elevation point (C) – Height of the lower elevation point (D)

(Rise)

= 1500 – 1000 = 500m

Horizontal distance = given line represent the distance along the hill slope where it is needed to calculate the slope. According to the scale given, we have to obtain horizontal distance.

Length between C-D is 2 units (use a ruler to find out this length).

According to the scale, 1unit = 1Km. So distance between C-D is = 2Km

Slop = 500feet/2mile = 250ft/mi

(42) Correct answer: (4)

According to the diagram, we can find the contour intervals as 100 feet

The point X is located in the 1600 feet contour line and there is no other contour line within that elevation zone. Therefore height of any point can be varied in the elevation rang between 1600 to 1699 feet. So, the possible highest elevation in this zone will be 1699 feet.

(17) Correct answer: (3) gentle slope and permeable soil

When rain water flows on the surface with the gentle slope, it tends to flows with low velocities than it on the steep slops. Water flows with low velocities take more time to move from one place to another place. It causes water to expose for a longer time durations to infiltrate (or sock downwards of the soil formations). Therefore infiltration capacity is higher at the gentle slops than at the steep slope with same conditions.

Permeable soils have higher infiltration capacities than impermeable soils. For example, in loose sand soils have higher infiltration capacity than clayey soils.

Therefore permeable soil with gentle slope surfaces allows the most infiltration of rain water.

(11) Correct answer: Option number (4)

The phases of the moon at any time are determined by the fraction of the moon’s sunlit hemisphere which one can see from the earth. Depending on the angle between the sun and moon, it gives different phases like full, crescent and dark moon.

As the sun – moon angle increases (like at the position 1) we see more of the sunlit (bright) part of the moon.