Section - A

1. What are the limitations of extracting energy from wind? 

2. Define power and hence derive its expression in terms of V, I & R. 

3. Define magnetic field. Why two magnetic field lines can never cross each other. Draw magnetic field lines due to circular current carrying coil.

SECTION - A

1. Why solar cookers are covered with glass plate and painted black from inside and outside. 

2. Define electric potential at a point. A current of 2A passes through circuit for 1 minute. If the potential difference between 2 terminals is  3V. Calculate work done in transferring charge between two terminals.

3. Give reasons:-

   a) If wire is stretched to double its length then its resistance becomes 4 times but resistivity remains same.

SECTION-A

1 State the role of the brain in reflex action.

2 What does the degree of closeness of the field lines represent ?

3 Name the part of a biogas plant where reactions take place in the absence of oxygen.

4 Consider the following chemical reaction :

   x+Water → Slaked lime

(a) Write the chemical name of 'x' and the type of reaction that occurs.

(b) Write chemical equation of the reaction.

SECTION-A

1 State the reason why covalent compounds are generally poor conductor of electricity ?

2 Give a way to prevent sexually transmitted diseases.

3 What is the meaning of Chipco Andolan ?

4 Explain giving reason the type of lens used to correct the defect of vision hypermetropia.

5 We should not use polybags as they are non biodegradable and cause pollution. How can we replace them to become environment friendly ?