441. What is the element required for solar energy conversion ______?
A. Ultra pure carbon
B. Silicon
C. Beryllium
D. Tantalum

442. An element that does not occur in nature but can be produced artificially is__________?
A. Plutonium
B. Uranium
C. Radium
D. Thorium

443. Muscle fatigue is caused by the accumulation of___________?
A. Uric acid
B. Lactic acid
C. Oxalacetic acid
D. Fyruvie acid

444. The total energy of revolving electron in an atom_____________
A. Will always be positive
B. Can never be positive
C. Can have any value above zero
D. Cannot be negative

445. The Virus of AIDS affects the growth of_____________?
A. Hemoglobin
B. RBCs in blood
C. T cells in blood
D. Grey Cells in blood

446. The vitamin which is generally excreted by humans in urine is__________?
A. Vitamin A
B. Vitamin B
C. Vitamin B12
D. Vitamin C

447. Which of the following metal occurs in free state ______________?
A. Lead
B. Iron
C. Mercury
D. Copper

448. Magnalium is an alloy of_____________?
A. Magnesium and Lead
B. Aluminium and Zinc
C. Aluminium and Magnesium
D. Aluminium and Mercury

449. By which process copper is refined ____________?
A. Roasting
B. Oxidation
C. Zone Refining
D. Electrolysis

450. In which part of the eye lies the pigment that decides the colour of the eyes of a person___?
A. Retina
B. Iris
C. Cornea
D. Pupal