Modern Materials and Chemicals

Porcelain is made for making crockery which is itself being prepared by______: Clay

Ceramics can conduct______: Do not conduct heat and electricity

Ceramics bear properties of______: High melting and boiling point, Hard, Chemically unreactive

Materials which can retain their strength above 550 C are known as______: Ceramics

Which of the following is a synthetic polymers? Plastics

Polymer comes from Greek words “poly” which means “many” and “meros” which means______: Part

The engineering materials known as “plastics” are more correctly called______: Polymers

What is a combination of two or more materials that has properties that the components materials do not have by themselves? Composite

Bakelite is a good______: Insulator

Natural substances made up of long molecules are______: Rubber and wool

Long chains of atoms are linked by______: Carbon

Materials which do not allow any light to pass through them are called______: Opaque materials

______ is a synthetic fibre used for making woolen cloths: Acrylic

Synthetic fibres are made using ______ as raw materials: Petrochemicals

Fibre obtained by chemical treatment of wood pulp is called______: Rayon

Nylon is obtained by______: Mixing coal, air and water

______ polyester used for making bottles, utensils, films: PET

Three dimensional molecules with cross links are formed in the case of a ______: Thermosetting plastic

Which is not polymer? Glucose

Which of the following is a polymer? Glycogen, Proteins, Natural rubber

If a substance such as heavy metals, pesticides accumulates in a body for a long time, it will be______: Passed on to next consumer in food chain

Pests may not be destroyed through______: Vaccine

Pesticides designed to kill birds are called______: Avicides

Pest control by changing crop spacing including crop rotation, pruning and weeding are part of the method of______: Cultural control

The three primary soil macro-nutrients are______: Potassium, Phosphorus, Nitrogen

The process of accumulating higher and higher amounts of a toxic material such as heavy metals within the body of any animal is called______: Bioaccumulation

If nitrogen is main element of fertilizers then fertilizers are classified as______: Nitrogen fertilizers

Increased ratio of chemical nutrients in ecosystem leads to______: Eutrophication

Greenhouse gas which can be emitted from storage of nitrogen-based fertilizers is______: Nitrous oxide

Organic fertilizers can be derived from______: Animal materials, Poultry materials, Plant materials

DDT stands for______: Dichloro-diphenyl tricholoroethane

Which material may also be considered a semiconductor element? Carbon

In “p” type material, charge carries would be______: Holes

When is a P-N junction formed? The point at which two opposite doped materials come together