646: The surface of the water in a lake is frozen and its temperature is -15°C. The maximum possible temperature of the water inside the lake in contact with the ice layer will be:
(a) 0°C
(b) 4°C
(c) 15°C
(d) Insufficient data to predict
647: What is/are the advantage/advantages of implementing the 'National Agriculture Market' (NAM) scheme?
1. It is a pan-India electronic trading portal for agricultural commodities.
2. It provides the farmers access to nationwide market, with prices commensurate with the quality of their produce.
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
648: The evidence for the rotation of stars comes mainly from the
(a) Doppler effect
(b) Photoelectric effect
(c) Stark effect
(d) Zeeman effect
649: Which one among the following is called philosopher's wool?
(a) Zinc oxide
(b) Zinc chloride
(c) Zinc nitrate
(d) Zinc bromide
Explanation:
Zinc Oxide (ZnO) is also called philosopher's wool burn in with a greenish blue flame when strongly heated in air forming clouds of light ZnO. ZnO is white power used as a pigment or in cosmetics or glass or inks and in zinc ointments.
650: Consider the following statements:
1. Smart Card is a plastic card with an embedded microchip.
2. Digital technology is primarily used with new physical communication medium such as satellite and fiber optics transmission.
3. A digital library is a collection of documents in an organised electronic form available on the internet only.
Which of the statements given above is/are correct?
(a) 3 only
(b) 1 and 2
(c) 2 and 3
(d) 1, 2 and 3