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
-
If a planet's mass were M/9 and its radius R/3 (M, R for the Earth), the free-fall acceleration at its surface would be (g = Earth's surface value):
सही उत्तर: घ) g
g ∝ M/R² = (1/9)/(1/3)² = 1, so it equals g.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
What fraction of the kinetic energy of a uniform solid cylinder that rolls on a level road without slipping is associated with its rotation?
सही उत्तर: क) 1/3
K_rot = ¼mv² and K_total = ¾mv², so the fraction is 1/3.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The moment of inertia of a uniform rod of mass M and length L about a perpendicular axis at a distance L/4 from one end is:
सही उत्तर: ग) 7ML²/48
The axis is L/4 from the centre: I = ML²/12 + M(L/4)² = 4ML²/48 + 3ML²/48 = 7ML²/48.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Masses of 1 kg, 2 kg and 3 kg are placed at (0, 0), (3, 0) and (0, 4) respectively (in metres). Their centre of mass is at:
सही उत्तर: घ) (1, 2)
x = (2 × 3)/6 = 1 and y = (3 × 4)/6 = 2.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A thin hollow sphere rolls down from rest without slipping through a vertical height h. Its speed at the bottom is:
सही उत्तर: ग) √(6gh/5)
mgh = ½mv²(1 + k²/R²) with k²/R² = 2/3, so v² = 2gh/(5/3) = 6gh/5.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A force of 10 N acts at a point 0.5 m from the axis of rotation, at an angle of 30° to the line joining the point to the axis. The torque is:
सही उत्तर: ख) 2.5 N m
τ = rF sin θ = 0.5 × 10 × sin 30° = 2.5 N m.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A uniform disc of mass 4 kg and radius 0.5 m rotates at 10 rad/s about its own axis. Its angular momentum is:
सही उत्तर: क) 5 kg m²/s
I = ½MR² = ½ × 4 × 0.25 = 0.5 kg m², so L = Iω = 5 kg m²/s.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A motor of efficiency 75% lifts a 200 kg load through 15 m in 30 s. The electrical power it draws is about (g = 10 m/s²):
सही उत्तर: ग) 1333 W
Useful output = mgh/t = 200 × 10 × 15/30 = 1000 W, so input = 1000/0.75 ≈ 1333 W.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
In a head-on perfectly elastic collision, a 2 kg sphere travelling at 6 m/s strikes a stationary 4 kg sphere. The 4 kg sphere moves off with a speed of:
सही उत्तर: घ) 4 m/s
v₂ = 2m₁u/(m₁ + m₂) = 2 × 2 × 6/6 = 4 m/s (the 2 kg ball rebounds at 2 m/s).
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A 0.5 kg block moving at 2 m/s on a smooth floor hits a spring of force constant 200 N/m. The maximum compression of the spring is:
सही उत्तर: क) 0.1 m
½mv² = ½kx² gives x = v√(m/k) = 2 × √(0.5/200) = 0.1 m.
💬 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।