2316: Optical fibre works on the principle of

(a) total internal reflection

(b) refraction

(c) scattering

(d) interference
2317: The process of light exposure in a 24-hour cycle that controls the growth and development of certain plants and animals is called:

(a) Photosynthesis

(b) Photoionisation

(c) Photoperiodism

(d) Photoluminescence
2318: NABARD, which is set up to provide loans for rural development, is a:

(a) Bank

(b) Board

(c) Block

(d) Department
2319: Three communicable diseases prevalent in developing countries caused by unsafe drinking water and bad sanitation are

(a) acute diarrhoea, cancer and gout

(b) malaria, acute diarrhoea and schistosomiasis

(c) onchocerciasis, leukaemia and arthritis

(d) rheumatism, malaria and AIDS
2320: With reference to Mughal India, what is/are the difference/differences between Jagirdar and Zamindar?

1. Jagirdars were holders of land assignments in lieu of judicial and police duties, whereas Zamindars were holders of revenue rights without obligation to perform any duty other than revenue collection.
2. Land assignments to Jagirdars were hereditary and revenue rights of Zamindars were not hereditary.

Select the correct answer using the code given below.

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2