Q30 of 30 Page 1

(a) Explain with the help of the pattern of magnetic field lines the distribution of magnetic field due to a current carrying a circular loop.

(b) Why is it that the magnetic field of a current carrying coil having


n turns, is 'n' times as large as that produced by a single turn (loop)?


(a) The magnetic field lines due to a current carrying circular loop can be shown with the help of following diagram:



Magnetic field lines are in the form of concentric circles in a circular current carrying conductor. Magnetic field lines are strong near the periphery because magnetic field lines remain close when they are near to the conductor


When we move towards the centre of the conductor, the magnetic field lines distant each other and at the centre, the arc appear of big circles.


On increasing the number of coils in the circular loop, the magnitude of the magnetic field increases and is equal to n times with n number of coils in the loop. It happens because the current in each circular coil has same direction and the field due to each coil just adds up.


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(b) Why are the traits acquired during the life time of an individual not inherited? Explain.


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(a) A gas is released during photosynthesis. Name the gas and also state the way by which the gas is evolved.

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(b) Give two reasons to explain why absorption of digested food occurs mainly in the small intestine.


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The position of certain elements in the Modern Periodic Table are shown below.

Using the above table answer following questions giving reasons in each case :


(i) Which element will form only covalent compounds?


(ii) Which element is a non-metal with valency 2 ?


(iii) Which element is a metal with valency 2 ?


(iv) Out of H, C and F which has largest atomic size?


(v) To which family does H, C and F belong?


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Define atomic size. Give its unit of measurement. In the modern periodic table what trend is observed in the atomic radius in a group and a period and why is it so?