Answer carefully: Guess a possible reason why water has a much greater dielectric constant (= 80) than say, mica (= 6).

Why water has very high dielectric constant?

Answer the following questions:The hysteresis loop of a soft iron piece has a much smaller area than that of a carbon steel piece. If the material is to go through repeated cycles of magnetisation, which piece will dissipate greater heat energy?

A spherical capacitor has an inner sphere of radius 12 cm and an outer sphere of radius 13 cm. The outer sphere is earthed and the inner sphere is given a charge of 2.5 muC . The space between the concentric spheres is filled with a liquid of dielectric constant 32. Compare the capacitance of this capacitor with that of an isolated sphere of radius 12 cm. Explain why the latter is much smaller.

The questions given below consist of an Assertion and Reason. Use the following key to choose of the appropriate answer. If both assertion and reason are CORRECT and reason if the CORRECT explanations of the assertion. If both assertion and reason are CORRECT but, reason is NOT THE CORRECT explanation of the assertion. If assertion is CORRECT explanation of the assertion. If both assertion and reason are INCORRECT. Assertion: Camphor is usually used in molecular mass determination Reason: Camphor has low cryscopic constant and therefore, causes greater depression is freezing point.

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : To compare the e.m.fs of two cells using a potentiometer, the e.m.f. of the cell in auxillary circuit must be greater than the e.m.fs of both the cells. Reason : The area of cross-section of the wire should be uniform and current through the wire should always be kept constant.

classically an electron can be in any orbit around nucleus of an atom. Then what determines the typical atomic size? Why is an atom not, say, thousand times bigger than its typical size? Thequestion had greatly puzzled Bohr before he arrived at his famous model of the atom that you have learnt in the text. To simulate what he might well have done before his discovery, let us play as followswith the basic constants of nature e, me, c and see if we can get a quantity with the dimensions of length that is roughly equal to the known size of an atom (~ 10 m).- You will find that the length obtained above is many orders of magnitude smaller than the atomic dimensions. Further, it involves c. But energies of atoms are mostly in non-relativistic domain where c is not expected to play any role. This is what may have suggested Bohr to discard c and look for else h had already made its appearance elsewhere. Bohr lay in recognising that h, m_e , and e will yield the right atomic size. Construct a quantity with the dimension of length from h, me, and e and confirm that its numerical value has indeed the correct order of magnitude.

Use deductive reasoning to answer the following: If it rains for more than four hours on a particular day, the gutters will have to be cleaned the next day. It has rained for 6 hours today. What can we conclude about the condition of the gutters tomorrow?

Each question contains STATEMENT-1 (Assertion) and STATEMENT-2( Reason). Examine the statements carefully and mark the correct answer according to the instruction given below: STATEMENT-1:For a chemical reaction at initial stage rate of forward reaction ( r_(f) ) is greater than rate of reversed reaction( r_(b) ) STATEMENT-2: When r_(f)=r_(b) ,chemical reaction is at equilibrium.