Question 71. Assertion (A): The frequency of floods in North Indian plains has increased during the last couple of decades.
Reasons (R): There has been reduction in the depth of river valleys due to deposition of silt.

Question 72. Which one of the following pairs of primitive tribes and places of their inhabitation is NOT correctly matched?

Question 73. The correct sequence in decreasing order of the four sugarcane producing States in India is :

Question 74. Consider the following statements :
1.Tides are of great help in navigation and fishing.
2.High tide enables big ships to enter or leave the harbour safely.
3.Tide prevents siltation in the harbours.
4.Kandla & Diamond Harbour are tidal ports.
Which of these statements are correct?

Question 75. Which of the following tributaries of the Ganga System flows northwards?

Question 76. Assertion (A): River Kalinadi is an east-flowing river in the southern part of India.
Reason (R): The Deccan Plateau is higher along its western edge and gently slopes towards the Bay of Bengal in the east.

Question 77. Match the following:
A.Flows between the Satpuras and the Vindhyas                   1. Mahanadi
B.Forms a delta in Orissa                                                         2. Narmada
C.Hemavati, Herangi and Amravati are tributaries                  3. Brahmaputra
D.River also known as Tsangpo                                               4. Cauvery
                                                                                                 5. Krishna

Question 78. Arrange the following rivers in descending order of their length:
1.Ravi
2.Cauvery
3.Sutlej
4.Yamuna

Question 79. Amravati, Bhavani, Hemavati and Kabini are tributaries of which one of the following rivers?

Question 80. Canal irrigation is most important in the Northern Plains of India because: