The Narmada River flows to the west, while most other large peninsular rivers flow to the east. Why? Select the correct answer using the codes given below.

Answer: (a) 1 only

Only the rift valley explains the westward flow.

Statement by statement

1. ✓ CORRECT The Narmada flows through a linear rift valley (a trough between faults), which runs east–west and opens towards the Arabian Sea.

2. ✗ NOT THE REASON It does flow between the Vindhyas and the Satpuras, but that describes its location — it does not explain the direction.

3. ✗ WRONG The Deccan plateau as a whole slopes EAST; that is why most peninsular rivers flow into the Bay of Bengal.

The idea

A rift valley is a long depression formed by movement along faults. It can guide a river across the broad regional slope of a plateau. Being between two ranges describes location; the fault-controlled valley and its gradient explain the drainage route.

Fault movement lowers a strip of crust → A linear valley forms → River occupies the trough → Local channel gradient guides flow → Narmada travels west → Water reaches the Gulf of Khambhat

Why the others are wrong

(b) The land slopes east, not west, and statement 2 is only a location.

(c) The general slope is towards the east.

(d) The rift valley is the reason.

The trap

Statement 2 is a true fact placed in a “why” question — true is not the same as the reason.

Elimination technique

The Deccan’s broad slope is eastward, so statement 3 fails. Statement 2 gives a location rather than the mechanism asked for; only statement 1 supplies the required explanation.

Also know

Tapi also occupies a fault-controlled westward valley. Most large Deccan rivers, including Godavari and Krishna, flow east. An estuary is a tidal river mouth; a delta forms where deposited sediment builds distributary channels. Mouth shape depends on sediment and marine processes, not direction alone.