Answer the questions : On which principle does the solar cooker work ?

Observe the picture carefully and answer the following questions: ( 1 ) State the category according to the food eaten by encircled organisms. ( 2 ) State the trophic level observed in the picture. ( 3 ) State two abiotic components of an environment. ( 4 ) Which is an important process of an ecosystem observed in a picture?

What are the advantages and disadvantages of using a solar cooker ? Are there places where solar cookers would have limited utility ?

Prove the following by using the principle of mathematical induction for all n in N (2n+1) lt 2^n , n >= 3

To study the structure and working of a solar cooker and/or water heater. Activity is done for understanding how the solar equipments are insulated and how does maximum heat absorption is ensured. Property : A black surface absorbs more heat. Structure : rarr It consists of an insulated metal box or a wooden box which is painted black from inside. rarr The box has a thick glass sheet as a cover over the box. rarr A plane or concave mirror is attached to the box that acts as a reflector. rarr Mirror focuses the rays of the sun into the box. State the advantages and limitations of using the solar cooker or solar water heater.

Observe the figure A and B given below and answer the following questions. (i) The power generation by the above two methods is non-polluting. True/False. (ii) List any two applications of solar energy (iii) What is a photovoltaic cell?

A graph of speed to time for a motin of a train is given. Study it and answer the following question . (1) Which type of motion would be from point 0 to A ? (2) Which type of motion does AB show ? (3) Find the retardation for the motion form point b to C .

The electricity bill of Atulbhai's house is more. So Sachin advised him to go for Government's subsidy scheme and put solar panels in his house. By doing so Atulbhai's electricity bill reduces. (1) In the solar panel the solar energy is converted into what form of energy ? (2) How many watts of electricity is produced from a typical solar cell when exposed to the sum ? (3) State the limitations of solar energy.

Prove the following by using the principle of mathematical induction for all n in N 3^(2n) when divided by 8, the ramained is always 1.

The temperature time graph given below shows the heating curve for pure wax. From the graph answer the following questions: a. What is the physical state of wax at the points A,B,C,D? b.What is the melting point of wax? c. What is its boiling point? d. Which portions of the graph indicate that change of state is taking place? e. Name the terms used for heat absorbed during the change of slates involved in above process.