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
-
When one prong of a tuning fork is loaded with a little wax, its frequency:
सही उत्तर: ग) decreases
Loading increases the vibrating mass, which lowers the natural frequency of the fork.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Ultrasonic waves are sound waves of frequency:
सही उत्तर: ख) above 20 kHz
Human hearing ranges from about 20 Hz to 20 kHz; waves above 20 kHz are ultrasonic.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A string 1 m long, fixed at both ends, carries transverse waves at 200 m/s. Its fundamental frequency is:
सही उत्तर: क) 100 Hz
For the fundamental mode λ = 2L = 2 m, so f = v/λ = 200/2 = 100 Hz.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A stationary source emits 400 Hz. An observer moves directly away from it at one-tenth the speed of sound. The frequency heard is:
सही उत्तर: घ) 360 Hz
f′ = f(v − v₀)/v = 400 × (1 − 0.1) = 360 Hz.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The second overtone of an organ pipe closed at one end is its:
सही उत्तर: ग) fifth harmonic
A closed pipe has only odd harmonics: fundamental = 1st, first overtone = 3rd, second overtone = 5th harmonic.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
If the amplitude of a sound wave is doubled (frequency unchanged), its intensity becomes:
सही उत्तर: ख) 4 times
Intensity is proportional to the square of the amplitude, so it becomes 2² = 4 times.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
When a sound wave passes from air into water, the quantity that remains unchanged is its:
सही उत्तर: क) frequency
Frequency is fixed by the source; speed and wavelength change in the new medium.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
Sound travels fastest in:
सही उत्तर: घ) steel
Sound speed v = √(E/ρ) is largest in solids such as steel (about 5000 m/s); it cannot travel in vacuum.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The solar constant (solar power received per unit area at the Earth's mean distance, outside the atmosphere) is about:
सही उत्तर: ग) 1.4 kW/m²
The solar constant is about 1.36 kW/m², i.e. roughly 1.4 kW per square metre.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A metal rod 1 m long (α = 1.2 × 10⁻⁵ K⁻¹) is heated through 100 K. Its increase in length is:
सही उत्तर: ख) 1.2 mm
ΔL = αLΔT = 1.2 × 10⁻⁵ × 1 × 100 = 1.2 × 10⁻³ m = 1.2 mm.
💬 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।