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
-
A copper calorimeter of mass 200 g has a specific heat of 0.09 cal g⁻¹ °C⁻¹. Its water equivalent is:
सही उत्तर: घ) 18 g
Water equivalent = mass × specific heat/(specific heat of water) = 200 × 0.09/1 = 18 g.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
When the temperature of a gas is raised, its coefficient of viscosity:
सही उत्तर: घ) increases
Gas viscosity comes from momentum transfer by molecules moving between layers; faster molecules at higher temperature transfer more momentum, so η increases (unlike liquids).
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The swing (curved path) of a spinning ball moving through air is explained by the:
सही उत्तर: ख) Magnus effect
Spin makes the air move faster on one side of the ball, lowering the pressure there (Bernoulli's principle), so a sideways force deflects the ball: the Magnus effect.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A steel ball of radius 1 mm falls through a liquid of viscosity 1 Pa s. If the density of steel exceeds that of the liquid by 7000 kg/m³, its terminal velocity is about (g = 10 m/s²):
सही उत्तर: ख) 1.6 cm/s
v = 2r²(ρ − σ)g/(9η) = 2 × 10⁻⁶ × 7000 × 10/9 ≈ 0.0156 m/s ≈ 1.6 cm/s.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
An ice cube floats in a glass filled to the brim with water. When the ice melts completely, the water level:
सही उत्तर: ख) remains the same
Floating ice displaces its own weight of water; on melting it becomes exactly that volume of water, so the level is unchanged.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The loss of strength of a material after it has been subjected to repeated alternating strain is called:
सही उत्तर: क) elastic fatigue
Elastic fatigue is the weakening caused by repeated cycles of stress, as in a wire bent back and forth until it breaks.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A pendulum bob is a hollow sphere full of water that slowly leaks out through a small hole at the bottom. As the water drains, the period of the pendulum:
सही उत्तर: ग) first increases and then decreases
As water leaves, the centre of mass first moves down (effective length increases) and then moves back up to the centre when the sphere is empty, so T first increases and then decreases to its original value.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A simple pendulum is taken inside an artificial satellite orbiting the Earth. Its time period becomes:
सही उत्तर: घ) infinite (it does not oscillate)
In free fall the effective g is zero, so T = 2π√(l/g_eff) becomes infinite: the bob does not swing back.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The orbital speed of a satellite in a circular orbit of given radius around the Earth:
सही उत्तर: ख) does not depend on the mass of the satellite
v₀ = √(GM/r) contains only the Earth's mass M and the orbit radius r.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The relation between gravitational field intensity E and gravitational potential V at a distance r is:
सही उत्तर: ख) E = −dV/dr
Field intensity is the negative gradient of potential, E = −dV/dr.
💬 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।