Ans: Ultra violet rays
F Ozone day- Sept 16
F Ozone layer was discovered by- Charles Fabry and Henry Buisson
F Ozone was discovered by- Christian shonbein
F Ozone layer can absorb between 93 and 99% of the ultra violet radiation from the sun
F Dobson meter used to measure the ozone levels in the stratosphere.
F One atom of chlorine can destroy more than a hundred thousand ozone molecule
2. Atom bomb is based on the principle of:
Ans: Nuclear fission
Ø Father of Atom bomb- Robert oppen Heimer
Ø Father of Indian Atom bomb- Dr. Raja Ramanna
Ø Father of hydrogen bomb- Edward Teller
Ø Father of Pakistan Atom bomb- Abdul Kadar Khan
3. "Mutation" theory was proposed by:
Ans: Hugo de Vries
4. First land plants are:
Ans: Bryophytes
The term "Bryophyte" comes from Greek work "Bryon"
5. The element which has most electro negativity:
Ans: Fluorine
w Fluorine is the lightest halogen, It is extremely reactive element.
w Fluorine isolated by French chemist Henri Moisson.
6. The tendency of a liquid drop to contract and occupy minimum area is due to:
Ans: Surface tension
Ä The cohesive forces between liquid molecules are responsible for the phonomenon known as surface tension.
Ä Surface tension is measured in dynes/ cm.
Ä The surface tension of water is 72 dyness/cm at 25°C
7. Light from the LASER is:
Ans: Monochromatic
ð LASER Light Amplification by Stimulated Emission of Radiation
ð Theodore - H-Maiman operated the first functioning LASER
ð LASER light consists of essentially one wave length, having its origin stimulated emission from one set of atomic energy levels
8. Study about bones are known as:
Ans: Osteology
§ Largest bone- Femur
§ Smallest bone- Stapes
§ There are 206 bones in the body of an adult
§ There are 300 bones in the body of an infant
§ There are five types of bones in the human body. These are long bones, short bones, flat bones, irregular bones and sesamoid bones
§ Long bones- Femur
§ Short bones- Carpals
§ Flat bones- Scapula
§ Irregular bones- Vertebrae
§ Sesamoid bones- Patella
9. Raman effects is due to _____ of light
Ans: Scattering
@ The blue colour of the sky is caused by scattering of light
@ Blue light has a short wave length
@ Red light has a longer wavelength
@ Red light has double the wave length of blue light
10. Sewage treatment is carried out with the help of:
Ans: Chlorella
· The name chlorella is taken from the Greek word Chloros, it means green. Chlorella is a genus of single-cell green.
· Chlorella is a single celled fresh water alga.
· Chlorella contains B-complex vitamins, Vitamin C, Iron and Carotenoids.
· 'Cyanobacteria' - the name comes from the Greek word ‘kyanos’.
· Cyanobacteria is also known as blue - green algae.
· Spirogyara is a genus of Filamentous charophyte green algae.
· Chara is a genus of green algae in the family characeae.
11. pH value of blood is:
Ans: 7.4
Ü Solutions with a pH less than 7 are said to be Acidic.
Ü Solutions with a PH greater than 7 are said to be basic or Alkaline.
Ü pH scale was introduced by Danish Chemist Soven Pedev Lauritz Sovensen.
Ü A pH of 7.0 is neutral
Ü pH is measured on the scale of 0 to 14 of the hydrogen ions in solution.
Ü The higher pH of any substance or solution, the more electrical resistance that substance or solution.
Ü Calcium helps maintain pH balance by neutralising the acids and toxins in the body.
12. The theory of 'jumping genes' was propounded by:
Ans: Barbara McClintock
F Transposable elements is known as 'Jumping genes'
F Transposable elements are DNA sequences that move from one location on the genome to another.
F Barbara McClintock's discovery of jumping genes earned her Nobel prize in 1983.
F Thomas Hunt Morgan, the first person to definitively link inheritance of a specific trait with a particular chromosome.
13. Nib of a pen is split keeping in view the phenomenon of:
Ans: Capillary
Ø Capillary Action is the result of adhesion and surface tension.
Ø Capillary action occurs when the adhesion to the walls is stronger than the cohesive forces between the liquid molecules.
Ø Capillary action, also known as capillarity.
14. Vulcanisation is the process of adding _____ to rubber.
Ans: Sulphur
@ Atomic number of Sulphur - (Z = 16)
@ It forms poly atomic molecules
@ It burns with blue flame
@ It is insoluble in water.
@ It is a multivalent non-metal
@ Hydrogen sulphide is smell of rotten egg.
@ It is used in Fungicides, Fertilizer, Batteries, Detergents, Gun powder and Match bon
@ Stibnite is known as Antimony Sulphide.
@ Lead sulphide is known as galena
@ Mercury Sulphide is known as Cinnabar
@ Zinc sulphide is known as Sphalerik.
