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Silicon is a tetra valent (4 valent) element, and in order to produce an n type semi-conductor, it has to be dropped with a penta valent (5valent)element, that, that is element in group five (v)

The electrons and cations of ionized gas act as charge carriers.

The ray which causes gas molecules to fluoresce or glow is the cathode rays

in a transformer, E S/E P = N s/N p where E s=e.m.f(voltage)of the secondary E p=e.m.f(voltage)of the primary N s=no.of turns in the secondary N p= no. of turns in the primary. since E s= V s; and E p= V p. V s/ V p= N s/N p ∴12/240= Ns/4000 Ns =(12x4000)/240 =200

the current in reverse biased junction diode is due to minority carriers, that is, the negative charges in the p-semi-conductor, and the positive charges in the n-semi-conductor.

Sodium is a soft, silvery-white metal that is a good conductor of electricity. It has free-moving electrons, which allows it to conduct electrical current efficiently

When the temperature difference between the wet bulb and dry bulb of a hygrometer is high, it indicates that the air is dry, leading to lower relative humidity. The wet bulb temperature drops more significantly because of evaporation, which occurs more readily in dry air. Conversely, a smaller temperature difference indicates higher humidity.

For liquid W, its mass = vol. x density = 3 x 200 =600kg. similarly, for liquid L, its mass = 7 x 150 = 1050kg ∴ Total mass of mixture = 600kg + 1050kg =1650kg. similarly total vol.of the mixture = 3m3 + 7m3 =10m3. ∴ density of the mixture = (Total Mass)/Total Mixture = (1650kg)/10m3 =165kgm-3

For anybody falling through a viscous liquid, at its terminal velocity. the resultant force acting on its is zero. from the equation: Mg - v - u = 0. where v = viscous drag U = upthrust Mg = weight of the body. ∴ 36 x 10 - 260 - U = 0 ∴ U = 360 - 260 = 100N Upthrust on the body = 100N.

Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. This movement occurs due to the random motion of particles, leading to an even distribution of substances over time.

Evaporation is a process by which molecules undergo a spontaneous transition from the liquid phase to the gaseous phase

Melting (I): This process involves the breaking of intermolecular forces as a solid turns into a liquid, reflecting the molecular structure of matter. Boiling (II): Similar to melting, boiling involves the transition from liquid to gas, indicating how molecules gain energy and move apart Conduction (IV): This is the process of heat transfer through collisions between molecules, demonstrating how molecular interactions lead to energy transfer.

When very hot water is poured into the thick glass tumbler, the inner surface of the glass heats up and expands more quickly than the outer part. This creates stress due to uneven expansion, leading to cracking. In contrast, the thin glass tumbler is less prone to this issue because it heats more uniformly.

Radio waves are used to transmit signals between satellites and ground stations because they can travel long distances and effectively penetrate the atmosphere.

For the device rated 2000 W, 250 V, implies that current I, flowing is given by the relation Power = IV I = (power)/v = (200)/250 = 8A. ∴ the most suitable fuse for the device is 8A