The forbidden energy gaps in conductors, semiconductors and insulators are (E_g)_c, (E_g)_s and (E_g)₁ respectively. What is the relation among them ?

A radioactive isotope phosphorous-32 has an initial activity 10μCi and has half life of 14 days. What is the activity of the source after 42 days?

The logic gate realised using p-n junction diodes in the given figure is:

A vertical electric field of magnitude 4.9×10⁵ NC^-1 just prevents a water droplet of mass 0.1 g from falling. What is the charge on the droplet? Take acceleration due to gravity 9.8 ms^-2.

A parallel beam of monochromatic light of wavelength 460 nm passes through a long slit of width 0.1 mm. What is the angular divergence in which most of the light is diffracted?

Which of the following statements are correct?
(A) The resistivity of a semiconductor decreases with increasing temperature.
(B) The potentiometer is unaffected by the internal resistance of the source.
(C) In ionic crystals and electrolytic liquids electrons carry the electric current.
(D) Ohm's law fails if V depends on I non-linearly.
(E) Kirchhoff's rules are used for analysis of electric circuits.
Choose the correct answer from the options given below: