3446: When a ship enters a sea from a river, its portion under water will:
(a) Increase
(b) Decrease
(c) Show no change
(d) Increase and decrease alternately
3447: Assertion (A) :
An iron ball floats on mercury but gets immersed in water.
Reason (R) :
The specific gravity of iron is more than that of mercury.
(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true but R is not a correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
3448: Which one of the following metals does not form amalgams ?
(a) Zinc
(b) Copper
(c) Magnesium
(d) Iron
3449: Consider the following statements
1. Most of the world's coral reefs are in tropical waters.
2. More than one-third of the world's coral reefs are located in the territories of
Australia, Indonesia and Philippines.
3. Coral reefs host far more number of animal phyla than those hosted by tropical rainforests.
Which of the statements given above is/are correct ?
(a) 1 and 2 only
(b) 3 only
(c) 1and 3 only
(d) 1, 2 and 3
3450: With reference to the treatment of cancerous tumours, a tool called cyberknife has been making the news. In this context, which one of the following statements is not correct ?
(a) It is a robotic image guided system
(b) It delivers an extremely precise dose of radiation
(c) It has the capability of achieving sub-millimetre accuracy
(d) It can map the spread of tumour in the body