Current Electricity — Physics STD 12 Science — Question

Two slits are separated by a distance of 0.5 mm and illuminated with light of λ = 6000 Å. If the screen is placed 2.5 m from the slits. The distance of the third bright image from the centre will be (a) 1.5 mm(b) 3 mm(c) 6 mm(d) 9 mm

Assertion :  The energy of charged particle moving in a uniform magnetic field does not change.
Reason    : Work done by magnetic field on the charge is zero.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion  : If the temperature of a semiconductor is increased then it's resistance decreases.
Reason      : The energy gap between conduction band and valence band is very small(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

If the distance of the far point for a myopia patient is doubled, the focal length of the lens required to cure it will become (a) Half  (b) Double  (c) The same but a convex lens  (d) The same but a concave lens  

A metallic solid sphere is placed in a uniform electric field. The electric field lines follow the path(s) shown in figure as

In LCR series AC circuit.

If a current increases from zero to one ampere in 0.1 second in a coil of 5mH, then the magnitude of the induced e.m.f. will be.