Govt. Exams
Entrance Exams
This problem requires using Newton's Second Law to find acceleration, then applying kinematic equations to determine final velocity.
Step 1: Find the Acceleration Using Newton's Second Law
Newton's Second Law states that the net force equals mass times acceleration. We need to rearrange to solve for acceleration.
Step 2: Apply the Kinematic Equation to Find Final Velocity
Since the object starts from rest (initial velocity = 0) and travels a distance of 5 m with constant acceleration, we use the equation that relates velocity, acceleration, and distance.
The velocity after traveling 5 m is 5√2 m/s (≈ 7.07 m/s). The answer is (A).
The Lyman series involves transitions to n=1 from higher energy levels. Balmer series ends at n=2, Paschen at n=3, and Brackett at n=4.
Charge Q = I × t, where I = 5 A and t = 10 s. Q = 5 × 10 = 50 Coulombs.
Centripetal acceleration a = v²/r = (10)²/5 = 100/5 = 20 m/s².
Refractive indices: Air ≈ 1, Water ≈ 1.33, Glass ≈ 1.5, Diamond ≈ 2.42. Diamond has the highest refractive index among these options.
For capacitors in series: 1/C = 1/C₁ + 1/C₂ = 1/2 + 1/3 = 5/6. Therefore C = 6/5 = 1.2 μF.
At maximum height, v = 0. Using v² = u² - 2gh: 0 = 20² - 2(10)h. 20h = 400. h = 20 m.
The Second Law of Thermodynamics states that entropy of an isolated system increases or remains constant. Heat spontaneously flows from hot to cold, not vice versa, establishing the direction of processes.
Kinetic energy KE = (1/2)mv². When velocity is doubled: KE' = (1/2)m(2v)² = (1/2)m(4v²) = 4 × (1/2)mv² = 4K.
The photoelectric effect occurs when light of frequency greater than or equal to the threshold frequency strikes a metal surface, causing electron emission. It demonstrates the particle nature of light.
