Magnetism And Matter — Physics STD 12 Science — Question

State Lenz’s Law.
A metallic rod held horizontally along east-west direction, is allowed to fall under gravity. Will there be an emf induced at its ends? Justify your answer.

Draw the nature of the graph of binding energy per nucleon against atomic mass number and explain its notable points.

Define the term ‘Half-life’ of a radioactive substance. Two different radioactive substances have half-lives T₁ and T₂ and number of undecayed atoms at an instant, N₁ and N₂, respectively. Find the ratio of their activities at that instant.

Draw a circuit diagram using a metre bridge and write the necessary mathematical relation used to determine the value of an unknown resistance. Why cannot such an arrangement be used for measuring very low resistances?

Explain the use of transformer for distribution of power over long distances.

Suppose the energy liberated in the recombination of a hole-electron pair is converted into electromagnetic radiation. If the maximum wavelength emitted is 820nm, what is the band gap?

Monochromatic light entering from one medium to another, its wavelength changes but the frequency does not change, explain.