Physics Teacher

Class XI Physics - Units & Measurements Worksheet Solutions Class XI Physics Chapter - 1: Units & Measurement Worksheet Solutions Q1. Calculate the length of the arc of a circle of radius 31 cm which subtends an angle of π/6 at the centre. Formula: The relation between angle (θ in radians), arc length (l), and radius (r) is given by: θ = l / r Given: Radius, r = 31 cm Angle, θ = π / 6 radians Solution: Rearranging the formula to find arc length: l = r ⋅ θ l = 31 cm × π / 6 Putting the approximate value of π ≈ 3.14: l ≈ 31 × 3.14 / 6 l ≈ 31 × 0.5233 l ≈ 16.22 cm Answer: The length of the arc is approximately 16.22 cm . Q2. Calculate the solid angle subtended by the periphery of an area of 1 cm 2 at a point situated symmetrically at a distance of 5 cm from the area. Formula: The solid angle (Ω) is defined as: Ω = A...

NCERT Physics: Point Object Concept Motion in a Straight Line: Point Object Analysis The Rule: If the distance moved by an object is much greater than its linear size , the object can be considered a "Point Object." POINT OBJECT (a) Railway Carriage Carriage Length: ~15 - 30 meters Distance (Station to Station): ~10 - 50 km Size is negligible compared to the distance between stations. POINT OBJECT (b) Man's Cap on Track Cap Diameter: ~0.2 meters Circular Track Length: ~400 meters The cap's dimensions are insignificant relative to the lap distance. NOT A POINT OBJECT (c) Spinning Cricket Ball Ball Diameter: ~0.07 meters Spin/Deviation: ~0.2 to 0.5 meters The dista...