भौतिक विज्ञान (Physics) – Physics MCQ
भौतिक विज्ञान (Physics) – इन्जिनियरिङ प्रवेश
Physics · Engineering Entrance – Mathematics, Physics, Chemistry & English · १,३९८ प्रश्न
१,३९८ प्रश्न उपलब्ध। मोड छान्नुहोस्:
भौतिक विज्ञान (Physics): प्रश्न र उत्तर
सही लागेको विकल्पमा थिच्नुहोस्। सही भए हरियो, गलत भए रातो देखिन्छ; ३ सेकेन्डपछि सही उत्तर र व्याख्या देखिन्छ।
सही: ० / ०
-
The moment of inertia of a thin uniform square plate of mass M and side a about one of its diagonals is:
सही उत्तर: ख) Ma²/12
By the perpendicular axis theorem the two diagonals share I_z = Ma²/6 equally, so I_diagonal = Ma²/12.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In a 'rotor' ride, people stand against the wall of a vertical cylinder of radius 2 m with μ = 0.5 between them and the wall. The floor can be removed safely once the angular speed reaches at least (g = 10 m/s²):
सही उत्तर: ग) about 3.2 rad/s
Friction μN = μmω²r must balance mg, so ω = √(g/(μr)) = √(10/1) ≈ 3.2 rad/s.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A 1000 kg car crosses the bottom of a dip (concave road) of radius 20 m at 10 m/s. The normal force on the car at the lowest point is (g = 10 m/s²):
सही उत्तर: ग) 15000 N
N − mg = mv²/r, so N = 1000(10 + 100/20) = 15000 N.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A ball dropped from a height of 10 m keeps bouncing on a floor with coefficient of restitution 0.5. The total distance it travels before coming to rest is about:
सही उत्तर: ख) 16.7 m
Each rebound height is e² times the previous, so the total distance = h(1 + e²)/(1 − e²) = 10 × 1.25/0.75 ≈ 16.7 m.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The potential energy of a particle moving along the x-axis is U = x³ − 3x (SI units). A position of stable equilibrium is:
सही उत्तर: घ) x = 1 m
dU/dx = 3x² − 3 = 0 at x = ±1; d²U/dx² = 6x is positive at x = 1 (minimum of U), so x = 1 m is stable.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A car of mass 1000 kg has an engine of maximum power 30 kW. If the total resistance to motion is a constant 1000 N, its maximum speed on a level road is:
सही उत्तर: ग) 30 m/s
At maximum speed the driving force equals the resistance, so v = P/F = 30000/1000 = 30 m/s.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A uniform rope lying on a smooth horizontal floor is pulled at one end by a horizontal force F. The tension at the midpoint of the rope is:
सही उत्तर: क) F/2
The whole rope accelerates at F/M; the rear half (mass M/2) is pulled only by the tension at the midpoint, so T = (M/2)(F/M) = F/2.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A curve of radius 50 m is banked at 45°, and the coefficient of friction between tyres and road is 0.5. The maximum safe speed is about (g = 10 m/s²):
सही उत्तर: घ) 38.7 m/s
v²max = rg(μ + tan θ)/(1 − μ tan θ) = 50 × 10 × 1.5/0.5 = 1500, so vmax ≈ 38.7 m/s.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A block rests on top of another block on a smooth floor; the coefficient of static friction between the blocks is μ. The lower block is pulled horizontally. The upper block does not slip as long as the acceleration does not exceed:
सही उत्तर: क) μg
Only friction accelerates the upper block, and the maximum friction is μmg, so the largest common acceleration is μmg/m = μg.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A 20 kg monkey climbs a rope that can withstand a maximum tension of 300 N. The greatest upward acceleration with which it can climb is (g = 10 m/s²):
सही उत्तर: ख) 5 m/s²
T − mg = ma gives a = (300 − 200)/20 = 5 m/s².
💬 टिप्पणी / गल्ती रिपोर्ट (०)
यी अभ्यास प्रश्न हुन्, आधिकारिक प्रश्न होइनन्। पाठ्यक्रम, विज्ञापन र नतिजाका लागि सम्बन्धित निकायको आधिकारिक वेबसाइट हेर्नुहोस्। उत्तरमा गल्ती भेटे प्रश्नमुनिको "टिप्पणी / गल्ती रिपोर्ट" मा लेख्नुहोस्।
नमस्ते! पाठ्यक्रम, सामान्य ज्ञान, भाषा परीक्षा वा कुनै प्रश्नको उत्तर बुझ्न सोध्नुहोस्।
AI ले गल्ती गर्न सक्छ। महत्वपूर्ण कुरा आधिकारिक स्रोतमा जाँच्नुहोस्।