The energy of electron in ground state of hydrogen is -13.6 eV. Ionization energy is MCQ with Answer and Explanation

Explanation:
h = ½gt² => t = √(2h/g) = √(40/10) = √4 = 2 s. Free fall formula. Final velocity v = gt = 20 m/s.

Explanation:
Potentiometer measures EMF and internal resistance. Formula: r = R(L₁ - L₂)/L₂, where R is shunt resistance, L₁ initial balancing length, L₂ after shunting. Here R=2Ω, L₁=60 cm, L₂=40 cm. Thus r = 2×(60-40)/40 = 2×20/40 = 1Ω. This derives from terminal voltage V = E - Ir and potentiometer principle V ∝ balancing length. Memory tip: 'r = R(L₁/L₂ - 1)'. This advanced numerical tests potentiometer applications, common in competitive exams for experimental physics. Always verify the formula derivation to avoid misapplication.

Explanation:
Displacement has both magnitude and direction, vector. Distance is scalar (path length). Speed scalar. Energy scalar. Vector examples: velocity, force, acceleration.