11.

Bakelite is used in making electrical appliances because it is a

• good conductor of heat

• good conductor of electricity

• good insulator of electricity

• thermoplastic

LED and CFL are very commonly used as sources of light in homes. Which of the following statements is true?

• LED is better because CFL contains toxic materials

• Both are equally good

• Neither of them is good because both contain toxic materials

• CFL is better because LED contains toxic materials

While investigating 'how water affects the germination of seeds', a teacher asked the students to soak bean seeds on a bed of cotton wool for a few days and observe the changes. What is the guideline that she forgot to mention? To place

• a few seeds on wet cotton

• many seeds on dry cotton

• a few seeds on dry cotton

• many seeds on wet cotton

The greenhouse effect which is causing an increase in the atmospheric temperature is mainly due to

• nitrogen

• sulphur

• carbon dioxide

• oxygen

Hormone Adrenaline

• helps the body to adjust stress level when one is very angry or worried

• helps control height

• helps control balance of electrolytes in the body

• helps control level of sugar in the blood

If the pressure over a liquid increases, its boiling point

• increases

• does not change

• first decreases and then increase

• decreases

The thumb of humans moves more freely than other fingers due to the presence of

• gliding joint

• hinge joint

• saddle joint

• pivotal joint

Four applicants for a post of TGT (Science) were asked to plan a lesson on 'Consequences of Deforestation'. Which one of the following lesson plans reflects the scientific approach?

• Provides a variety of examples to explain the concept

• Includes activities that children can perform in groups and draw conclusions through a PowerPoint presentation

• Mentions about the use of ICT to help students understand the concept

• Explains in detail the consequences of deforestation

The main aim of conducting Mathematics and Science Olympiads is to

• grade students according to their capabilities

• help students score high marks in professional examinations

• grade schools based on the performance of their students

• promote excellence in the subject by nurturing creativity and experimentation

Non-metallic oxides

• are basic in nature

• are amphoteric in nature

• turn red litmus paper blue

• are acidic in nature