Govt. Exams
Charge Q = I × t, where I = 5 A and t = 10 s. Q = 5 × 10 = 50 Coulombs.
Refractive indices: Air ≈ 1, Water ≈ 1.33, Glass ≈ 1.5, Diamond ≈ 2.42. Diamond has the highest refractive index among these options.
Gravitational force is always attractive, acts between any two masses, is independent of the medium, and is governed by Newton's law of universal gravitation.
Using v = u + at, where u = 0, v = 20 m/s, a = 2 m/s². 20 = 0 + 2t, so t = 10 seconds.
At sunset, light travels through a longer path in the atmosphere. Shorter wavelengths (blue) scatter more (Rayleigh scattering), leaving longer wavelengths (red) to reach the observer.
Using lens formula: 1/f = 1/u + 1/v. 1/15 = 1/30 + 1/v gives v = 30 cm. When u = 2f, image forms at 2f with magnification -1 (same size, inverted, real).
Electric potential is defined as work done per unit charge. SI unit is Joule/Coulomb = Volt. Option D (Watt/Ampere) also equals Volt but option A is more fundamental.
The visible light spectrum ranges from violet (shortest wavelength ~400 nm) to red (longest wavelength ~700 nm). Red light has the longest wavelength among visible light.
Using F = ma, F = 2 × 5 = 10 N. This is a direct application of Newton's Second Law.
Newton's Second Law: F = ma, where acceleration is directly proportional to force and inversely proportional to mass.