Govt. Exams
Entrance Exams
Using P = V²/R, we get R = V²/P = (250)²/1000 = 62500/1000 = 62.5 Ω.
Rayleigh scattering causes shorter blue wavelengths to scatter more effectively than longer red wavelengths when sunlight passes through the atmosphere, making the sky appear blue.
In beta-minus decay, a neutron converts to a proton, emitting an electron (beta particle) and an antineutrino. This increases atomic number by 1.
An alpha particle is a helium-4 nucleus (₂He⁴) with 2 protons and 2 neutrons. Alpha decay decreases atomic number by 2 and mass number by 4. Alpha particles have low penetration power.
Using transformer equation: Vₛ/Vₚ = Nₛ/Nₚ. Vₛ = 220 × (500/100) = 220 × 5 = 1100 V.
The Weber (Wb) is the SI unit of magnetic flux, defined as Tesla × meter². 1 Wb = 1 T·m².
A tungsten filament's resistance changes significantly with temperature during operation, making it non-ohmic. Metals at constant temperature follow Ohm's law.
Total resistance = 4 + 6 = 10Ω. Using Ohm's law: I = V/R = 10/10 = 1 A.
Using Snell's Law: n₁sinθ₁ = n₂sinθ₂. 1 × sin(30°) = 1.5 × sinθ₂. 0.5 = 1.5sinθ₂. sinθ₂ = 0.333. θ₂ ≈ 19.47°.
Diffraction is the bending of waves around obstacles or through openings. This explains why we can hear sounds around corners.
