Solution

(a) Force on charge Q at B due to charge q at A

Solution

(a) Conductivity of a metallic wire is defined as its ability to allow electric charges or heat to pass through it. Numerically, the conductivity of a material is reciprocal of its resistivity.SI unit : ohm⁻¹ m⁻¹ or mho m⁻¹ or Siemen m⁻¹.
(b) Consider a potential difference V be applied across a conductor of length l and cross-section A.
Electric field inside the conductor, E = v/l.
Due to the external field the free electrons inside the conductor drift with velocity vᵈ.
Let number of electrons per unit volume = n,
charge on an electron = e
Total electrons in length, l = nAl
total charge, q = neAl

Solution

Solution

Solution

Solution

(b) If instead of monochromatic light, white light is used, then the central fringe will be white and the fringes on either side will be coloured. The blue colour will be nearer to the central fringe and the red will be farther away. The path difference at the centre on the perpendicular bisector of slits will be zero for all colours and each colour produces a bright fringe thus resulting in a white fringe. Further, the shortest visible wave, blue, produces a bright fringe first.

Solution

Given, refractive index of lens,
μ(g)=1.5
The distance of the needle from the lens in the first case = The focal length of the combination of convex lens and plano- concave lens formed by the liquid, f =x
And, the distance measured in the second case = Focal length of the convex lens,
f1=y
If the focal length of the plano-concave lens formed by the liquid be f2 then,

Solution

Bohr's postulate for stable orbits in hydrogen atom: An electron can revolve only in those circular orbits in which its angular momentum is an integral multiple of h/2π.
If n is the principal quantum number of orbit, then an electron can revolve only in certain orbits or definite radii. These are called stable orbits.De Broglie explanation of stability of orbits:
According to de Broglie, orbiting electron around the nucleus is associated with a stationary wave. Electron wave is a circular standing wave. Since destructive interference will occur if a standing wave does not close upon itself, only those de Broglie waves exist for which the circumference of circular orbit contains a whole number of wavelengths i.e., for orbit circumference of
nth orbit as 2πrₙ.
2πrₙ=nλ
2πrₙ=n(h/mv)
mvrₙ=nh/2π, which is the quantum condition proposed by Bohr.

Solution

(a)The value of binding energy per nucleon gives a measure of the stability of that nucleus greater is the binding energy per nucleon of a nucleus, the more stable is the nucleus.

The saturation effect of nuclear forces is the property responsible for the approximate constancy of binding energy in the range 30<A<17030<A<170.
It is clear from the curve that the binding energy per nucleon of the fused nuclei is more than that of the light nuclei taking part in nuclear fusion.Hence, energy gets released in the process.
(b)

Solution

(a) In order to convert alternating current into direct current, she can use full-wave rectifier. A full-wave rectifier uses two diodes, which enables it to pass both the positive and the negative side of the alternating current input. The diodes are connected to the transformer.The full-wave rectifier requires that you use a center-tapped transformer. The diodes are connected to the two outer taps, and the center tap is used as a common ground for the rectified DC voltage. The full-wave rectifier converts both halves of the AC sine wave to positive-voltage direct current.

(b) The truth table and circuit symbol for NAND gate: