41. Which of the following gas is used in the cigarette lighter?
42. Which one among the following can produce light by a chemical change?
A. Electric Bulb
D. Lightning and thunder
43. The colors of the firecrackers are extracted from the elements of the salt of –
A. Zn and S
B. Cr and Ni
C. Sr and Ba
D. K and Hg
44. Cobalt-60 is commonly used in radiation therapy because it emits –
A. Alpha rays
B. ß Rays
C. ? Rays
D. X – Rays
Read More ? Basic Terms in Thermodynamics
45. Which one of the following polymeric materials are used for making bulletproof jackets?
B. Nylon 6,6