Science Group
Explore subjects and practice MCQs
7
Chapters
1,610
Total MCQs
Science Group
Answer: P = I²R = 3² × 10 = 9 × 10 = 90 W
Answer: Charge Q = It, so the SI unit is Coulomb (C)
Answer: I = V/R = 12/4 = 3 A
Answer: W = QV = 5 × 10 = 50 J
Answer: Q = mcΔT = 2 × 4200 × 5 = 42000 J
Answer: Water boils at 100°C (373 K) at standard atmospheric pressure.
Answer: During phase change (melting), the temperature remains constant at the melting point.
Answer: Impulse = Force × time = N·s, and from momentum change it is also kg·m/s. Both are equivalent.
Answer: KE = ½mv² = ½ × 1 × 9 = 4.5 J
Answer: The orbital velocity near Earth\'s surface is v = √(gR) ≈ 7.9 km/s
Answer: A single movable pulley provides a mechanical advantage of 2
Answer: By conservation of momentum: mv - mv = 2mv\' → v\' = 0
Answer: h = ½gt² → 80 = ½ × 10 × t² → t² = 16 → t = 4 s
Answer: Pitch = distance moved per rotation = 1 mm (given), least count = 1/50 = 0.02 mm
Answer: F = ma, so dimension of force = [M][LT⁻²] = [MLT⁻²]
Answer: Weight on Moon = W/6 ≈ 49/6 ≈ 8.17 N ≈ 8.2 N
Answer: Displacement has both magnitude and direction, making it a vector quantity.
Answer: Escape velocity = √(2gR) ≈ 11.2 km/s
Answer: Buoyant force = weight in air - apparent weight = 20 - 16 = 4 N
Answer: Light travels fastest in vacuum (c = 3 × 10⁸ m/s), which is the universal speed limit.