Question

Assertion (A): In the upper course, the dominant activity of a river is erosion.

Reason (R): The river flows swiftly as the gradient is steep.

Options

• Both A and R are true, and R is the correct explanation of A.

• Both A and Rare true, but R does not explain A.

• A is true, but R is false.

• A is false, but R is true.

Answer 1

Both A and R are true, and R is the correct explanation of A.

Explanation:

In the upper course of a river, the dominant activity is erosion due to the steep gradient. The steep slope causes the river to flow swiftly, giving it high energy, which leads to significant erosion of the riverbed and banks. Therefore, the steep gradient directly causes the swift flow, which explains why erosion is dominant in the upper course of the river.