Electromagnetic Waves — Physics STD 12 Science — Question

The energy gap of silicon is 1.14 eV. The maximum wavelength at which silicon will begin absorbing energy is(a) 10888 Å(b) 1088.8 Å(c) 108.88 Å(d) 10.888 Å

Resolving power of a telescope increases with:

When a slab of dielectric material is introduced between the parallel plates of  a capacitor which remains connected to a battery, then charge on  plates relative to earlier charge(a) Is less(b) Is same(c) Is more(d) May be less or more depending on the nature of the material introduced

Two ends of a conductor are at different temperatures the electromotive force generated between two ends is(a) Seebeck electro motive force (e.m.f.)(b) Peltier electro motive force (e.m.f.)(c) Thomson electro motive force (e.m.f.)(d) None of these

Assertion :   X-rays cannot be diffracted by means of grating.
Reason     : X-rays does not obey Bragg's law.(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.

Permanent magnets are made from:

A current-carrying, straight wire is kept along the axis of a circular loop carrying a current. The straight wire:

A wire of length L carrying current i is placed perpendicular to the magnetic induction B. The total force on the wire is