306: With reference to Indias satellite launch vehicles, consider the following statements:
1. PSLVs launch the satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites.
2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth.
3. GSLV Mk III is a four-staged launch l vehicle with the first and third stages l using solid rocket motors; and the second and fourth stages using liquid rocket engines.
Which of the statements given above is/are correct.?
(a) 1 only
(b) 2 and 3
(c) 1 and 2
(d) 3 only
307: Assertion
Carbon dioxide in air is necessary for sustaining life
Reason
Carbon dioxide is assimilated in carbohydrates in photosynthesis
(a) if A and R both are correct and R is the correct explanation of A
(b) if A and R both are correct but R is not the correct explanation of A
(c) if A is correct and R is incorrect
(d) if A is incorrect and R is correct
308: When water is heated from zero Degree Celsius to Ten Degree Celsius, its volume
(a) increases
(b) decreases
(c) does not change
(d) first decreases and then increases
Explanation:
When water heated from 0 degree C to 10 degree C its volume first decreases and then increases because of "anomalous expansion" of water. Water has the maximum density and minimum volume at 4 degree C and as temperature increases or decreases.
309: The function of the liver is to:
(a) Promote digestion of food
(b) Dilute fat
(c) Store glucose as glucogen
(d) None of these
310: Consider the following statements :
In a nuclear reactor, self-sustained chain reaction is possible, because
I. more neutrons are released in each of the fission reactions.
II. the neutrons immediately take part in the fission process.
III. the fast neutrons are slowed down by Graphite.
IV. every neutron realeased in the fission reaction initiates further fission.
Which of these statements are correct ?
(a) I, II and III
(b) I and III
(c) II and IV
(d) II, III and IV
Explanation:
In a nuclear raachtor, control rods made of Boron steel, or cadmium, which are capable of absorbing neutrons and are used to ensure that the neutron flux is under control. The control rods are inserted in the reactor and can be raised or lowered to control the chain reaction.