The correct option is (a) 1, 2 and 3 only.
Explanation
The Ganga river system is fed by tributaries from two main sources: the Himalayas in the north and the Peninsular Plateau in the south. The Himalayan tributaries are generally perennial, originating from glaciers, while Peninsular tributaries are rain-fed.Statement-wise Analysis:
- 1. Ghaghara: Correct. The Ghaghara originates in the glaciers of Mapchachungo (near the Tibet-Nepal border). It flows through Nepal, where it is known as the Karnali, and joins the Ganga in India. It is a major Himalayan tributary.
- 2. Gandak: Correct. The Gandak rises in the Nepal Himalayas between Dhaulagiri and Mount Everest. It drains the central part of Nepal and enters the Ganga plain in Bihar.
- 3. Kosi: Correct. The Kosi is an antecedent river with its source to the north of Mount Everest in Tibet, where its main stream, the Arun, rises. It flows through Nepal, collecting tributaries like the Sun Kosi and Tamur, before entering India.
- 4. Chambal: Incorrect. The Chambal does not originate in the Himalayas. It rises near Mhow in the Malwa Plateau of Madhya Pradesh. It is a major tributary of the Yamuna and belongs to the Peninsular drainage system.
Key Takeaway: The Ghaghara, Gandak, and Kosi are major left-bank tributaries of the Ganga originating in the Nepal Himalayas, whereas the Chambal is a tributary of the Yamuna originating from the Peninsular Plateau.