1151. How soon after contamination by mosture does a zinc containing amalgam restoration start expanding ?

A. 12 Days
B. 1-2 Days
C. 3-5 Days *
D. One week

1152. Which of the following statements is true regarding lathe cute silver alloy ?

A. Requires least amount of mercury
B. Achieves lowest compressive strength at one hour *
C. Has tensile strenght both at 15 minutes and 7 days and is comparable to highe copper unicompositional alloys
D. Has lower creep value

1153. Creep value of which of the following is the highest ?

A. Low copper amalgam alloy *
B. Admix alloy
C. Single composition alloys
D. Cree value of all above mentioned alloys is same

1154. How muct fraction of methyl mercury is absorbed from the gut :

A. 20%
B. 50%
C. 80%
D. 100% *

1155. What fraction of inhaled mercury vapour is retained in the body ?

A. 45-55%
B. 55-65%
C. 65-85% *
D. >85%

1156. The lowest blood mercury level at which the earliest specific symptom starts appearing at :

A. 25 ng/ml
B. 35 ng/ml *
C. 40 ng/ml
D. 45 ng/ml

1157. Corrosion of amalgam restoration :

A. Can extend upto a depth of 100-500 um *
B. Decrease if tin content of alloy increases
C. Is promoted by gamma phase of alloy particles
D. Is resisted the most by copper-tin phase in high copper amalgam

1158. Over-trituration of silver alloy and mercury :

A. Reduce contraction
B. Increases the strenght of althecut alloy but reduces the strenght of spherical alloy amalgam *
C. Decreases creep
D. Gives a dull and crumbly amalgam mix

1159: The range of wavelenght of visible light curing system is :

A. 400-700 nm
B. 410-500 nm *
C. 365-400 nm
D. 700-900 nm

1160. Which of the following is not true about hand instrument used in operative density:

A. They are generally made of stainless steel
B. Nickel cobalt chromium is never used in tis fabrication *
C. Carbon steel is more efficient than stainless steel
D. It can be made with stainless steel with carbide inserts