The efficiency of a Carnot engine working between 27°C and 127°C is MCQ with Answer and Explanation

Explanation:
Diffraction (bending around obstacles) is wave phenomenon explained by Huygens' principle. Particle model predicts straight-line propagation. Memory aid: 'Diffraction/interference ⇒ wave nature; photoelectric ⇒ particle nature'. Wave-particle duality frequently tested in competitive exams.

Explanation:
Work done by a variable force is the definite integral of F dx. W = Integral(3x^2 + 2x) dx from 1 to 2. W = [x^3 + x^2] evaluated from 1 to 2. Upper limit: (2^3 + 2^2) = 8 + 4 = 12. Lower limit: (1^3 + 1^2) = 1 + 1 = 2. Work = 12 - 2 = 10 Joules.

Explanation:
By definition, the electric potential difference between two points in an electric field is the amount of external work required to move a unit positive charge (1 Coulomb) slowly and without acceleration from one point to the other against the electrostatic force. The SI unit of potential difference is the Volt (Joules/Coulomb).