भौतिक विज्ञान – Physics MCQ
भौतिक विज्ञान – कृषि/वन प्रवेश
Physics · Agriculture, Veterinary & Forestry Entrance · ४२५ प्रश्न
४२५ प्रश्न उपलब्ध। मोड छान्नुहोस्:
भौतिक विज्ञान: 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 principle behind the operation of a hydroelectric power plant is based on which of the following physical concepts?
सही उत्तर: क) Conservation of Energy
Hydroelectric plants utilize the potential energy of water at a height, converting it into kinetic energy as it flows downhill. This kinetic energy then drives turbines connected to generators, generating electricity. The other options – Newton’s laws, wave propagation and thermodynamics – are not fundamental principles directly involved in hydroelectric power generation. 2023
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The energy of the Sun is primarily produced through:
सही उत्तर: ग) Nuclear fusion
The Sun's energy comes from nuclear fusion reactions occurring in its core, where hydrogen atoms fuse to form helium, releasing enormous amounts of energy. Nuclear fission and radioactive decay produce much smaller amounts of energy.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The principle of operation of a simple electric motor relies primarily on:
सही उत्तर: क) Electromagnetic induction
A simple electric motor works based on the interaction between magnetic fields and electric currents. This is known as electromagnetic induction. The other options are incorrect principles that don’t directly explain how a motor functions. The most plausible alternative is Newton's third law.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A stone is dropped vertically downwards from a height of 20 meters above the ground. Taking g = 9.8 m/s², what will be the velocity of the stone just before it hits the ground?
सही उत्तर: ग) 28 m/s
We can use the equation of motion: v² = u² + 2as, where v is final velocity, u is initial velocity (0 m/s), a is acceleration (g = 9.8 m/s²) and s is distance (20m). Therefore, v² = 0² + 2 * 9.8 * 20 = 392. Then v = √392 ≈ 19.8 m/s which is closest to 20 m/s.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Two forces of magnitude 5 N acting at a point with an angle of 60° between them will produce a resultant force whose magnitude is closest to:
सही उत्तर: क) 7.07 N
The resultant force can be calculated using the law of cosines. Let F1 and F2 be the two forces, with angle θ between them. The magnitude of the resultant (F) is given by F = √(F1² + F2² + 2F1F2cosθ). In this case, cos60° = 0.5, so F = √ (5² + 5² + 2*5*5*0.5) = √(25+25+25) = √75 ≈ 8.66 N. The closest option is 10N which is a reasonable approximation.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
If a wave travels from a medium with a higher refractive index to a medium with a lower refractive index, what happens to its speed?
सही उत्तर: ख) B. The speed decreases
Option B is the correct answer. The speed of a wave is inversely proportional to the refractive index of the medium it travels through (v = c/n, where v is speed, c is speed in vacuum and n is the refractive index). A lower refractive index implies a reduced speed.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A uniform wire loop is swinging with angular displacement θ. Which of the following statements is true regarding the torque acting on it?
सही उत्तर: क) A. The torque is proportional to sin(θ)
Option A, that the torque is proportional to sin(θ), correctly describes the rotational force experienced by the rotating loop. This relates directly to the perpendicular distance from the axis of rotation (radius) and the tangential component of the linear velocity (which depends on θ). Options B, C, and D are inaccurate representations of torque.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
What is the SI unit for measuring electric field strength?
सही उत्तर: ग) C. Newton per Coulomb
Option C, Newton per Coulomb (N/C), is the correct definition of electric field strength. It represents the force experienced by a test charge divided by the magnitude of that charge. A volt measures potential difference, an ampere measures current, and an ohm measures resistance.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The principle behind the operation of a Wheatstone bridge is based on which fundamental concept?
सही उत्तर: क) A. Ohm’s Law
Option A, Ohm’s Law, is the correct answer. A Wheatstone bridge uses a balanced voltage between two resistors to determine an unknown resistance, relying on the relationship between voltage (V), current (I) and resistance (R). Options B and D are irrelevant, while C incorrectly suggests balance of potential differences - it's the *ratio* of resistances that matters.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A force F is applied to a block of mass m, which moves with an acceleration a. If the same force is applied to another block of the same mass m on a frictionless surface, what will be the acceleration?
सही उत्तर: ख) 2a
According to Newton's second law (F = ma), for each case, the equation holds. In this scenario, the force is applied to both blocks. Therefore, for the first block, a = F/m and for the second block, also a=F/m because there’s no friction. This means acceleration will be a
💬 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।