Ques. No. 19

Ques. No. 19 •et o H" vatton. (b) Write two properties of magnetic field lines. 15. Name three different glands associated With the digestive system in hu 3 V Secretions. name 16. (a) Name the hormone which is secreted When growjng Plants secretion in a plant. (b) Explain why do plants to bend towards 3 of (a) Name the diseases bv a person to (B) How the timing of secretion and amount of in 0K (a) ust four factors that should be taken into an of good of (b) How does burning of fossil fuel cause water polluuon? (c) It you could use any source of energy for heating your food which one and why? 19. (a) Explain what is geothermal energy? (b) Write its one advantage and one limitatiqrv• (c) Define (OTE). (d) Write one advantage Of nuclear fission reaction. 20. (a) Explain the Steps for extraction Of copper from its ore. Write the reaction inwved- S (b) Draw a neat, labelled diagram for electrolytic refining of copper and explain the process. 21. (a) Identify the compound ofcalcium which is yellowish white powder and is used for disinfecting drinking water. Write its chemical name and formula. How is it manufa«ured? Write the chemical equation for the reaction involved. Also list two other uses Of the compound. (b) Write the balanced chemical equation of chlor-alkali process. 2 . (a) Resistors given as RI, R, and R, are connected in series to a battery V. Draw the circuit diagram showing the arrangement. Derive an expression for the equivalent resistance of t combination. (b) If RI = 100, Ra = 20 Q and R! = 30 0, Calculate the effective resistance when they are connected in series to a battery 6 V. also find the current flowing in the circuit.