General Studies: Physics Electricity ke liye free mock test: 36 questions, timer, negative marking aur explanation ke saath. Koi login nahi, koi payment nahi — turant shuru karein.
General Studies: Physics Electricity ke liye ye 36 questions ka practice set General Knowledge pattern par banaya gaya hai. Test me 45 second per question ka timer hai aur har galat answer par 0.25 marks kate jaate hain — bilkul asli exam jaisa. Submit karne ke baad aapko exact score, accuracy aur har question ka explanation milta hai. Bihar ke competitive exams (BPSC, BSSC, Bihar Police, BTSC) ki tayari karne wale students ke liye.
Neeche is set ke kuch questions hain — inhi par aapka timed test banega. Answer dekhne ke liye “Answer” par click karein.
Before the discovery of electrons, scientists defined the direction of electric current based on the flow of positive charges. In modern circuit design, how is the conventional direction of electric current designated relative to actual charge carriers?
इलेक्ट्रॉनों की खोज से पहले, वैज्ञानिकों ने धनात्मक आवेशों के प्रवाह के आधार पर विद्युत धारा की दिशा को परिभाषित किया था। आधुनिक सर्किट डिज़ाइन में, वास्तविक आवेश वाहकों के सापेक्ष विद्युत धारा की पारंपरिक दिशा को कैसे निर्दिष्ट किया जाता है?
(A) It aligns perfectly parallel to the drift velocity vector of negative electrons.
(B) It flows exclusively from a lower electric potential to a higher electric potential channel.
(C) It shifts dynamically depending on the macroscopic cross-sectional area of the wire.
(D) It is conventionally taken as opposite to the direction of the flow of electrons.
✅ Answer & Explanation
Sahi jawab: D) It is conventionally taken as opposite to the direction of the flow of electrons.Explanation: Conventionally, current ki direction ko positive charge ke flow ki taraf mana jata hai. Circuit me actual flow electrons (negative charge) ka hota hai, isliye conventional current hamesha electrons ke flow ke opposite direction me liya jata hai.
An ammeter is a standard instrument used to track the magnitude of electric current traversing a circuit. To ensure an accurate measurement without altering the circuit parameters, how must it be connected?
एक एमीटर एक मानक उपकरण है जिसका उपयोग सर्किट से गुजरने वाले विद्युत धारा के परिमाण को मापने के लिए किया जाता है। सर्किट मापदंडों को बदले बिना सटीक माप सुनिश्चित करने के लिए, इसे कैसे जोड़ा जाना चाहिए?
(A) It is always connected in series in the circuit through which the current is to be measured.
(B) It must always be connected in parallel across the specific target gadget.
(C) It must be oriented at an orthogonal angle of 90 degrees relative to the cell terminals.
(D) It is connected in a bridged configuration only when the circuit is open.
✅ Answer & Explanation
Sahi jawab: A) It is always connected in series in the circuit through which the current is to be measured.Explanation: Ammeter ko hamesha series me connect kiya jata hai taaki pura current uske through pass ho sake. Sath hi iska internal resistance bahut low hona chahiye taaki ye circuit ke total current ko change na kare.
Electric charges do not flow through a copper wire by themselves, just as water in a perfectly horizontal tube does not flow. To initiate and sustain a current, what physical condition is mandatory along the conductor?
विद्युत आवेश किसी तांबे के तार में अपने आप प्रवाहित नहीं होते, ठीक वैसे ही जैसे एक पूर्णतः क्षैतिज नली में पानी प्रवाहित नहीं होता। धारा को प्रारंभ करने और बनाए रखने के लिए, चालक के अनुदिश कौन सी भौतिक स्थिति अनिवार्य है?
(A) The gravitational acceleration vector must align parallel to the wire axis.
(B) The conductor must undergo immediate mechanical polarization at its boundaries.
(C) There must be a difference of electric pressure, called the potential difference, along the conductor.
(D) The total internal chemical energy matrix must drop to absolute zero.
✅ Answer & Explanation
Sahi jawab: C) There must be a difference of electric pressure, called the potential difference, along the conductor.Explanation: Jaise pani ko flow karne ke liye pressure difference chahiye hota hai, waise hi electrons ko move karne ke liye conductor ke dono ends ke beech electric potential difference (V) ka hona zaroori hota hai.
When no current is being drawn from an electric cell, what is the status of the potential difference across its terminals generated by the internal chemical actions?
जब किसी विद्युत सेल से कोई धारा नहीं ली जा रही होती है, तो आंतरिक रासायनिक क्रियाओं द्वारा उसके टर्मिनलों पर उत्पन्न विभवांतर (potential difference) की स्थिति क्या होती है?
(A) The potential difference collapses instantly to absolute zero.
(B) The potential difference transforms into an alternate transverse magnetic field tensor.
(C) The value fluctuates rapidly as a function of the external environment pressure.
(D) The potential difference remains actively generated across the terminals even when no current is drawn.
✅ Answer & Explanation
Sahi jawab: D) The potential difference remains actively generated across the terminals even when no current is drawn.Explanation: Cell ke andar ho rahe chemical reactions terminals ke beech potential difference continuously bana ke rakhte hain, chahe circuit open ho aur cell se koi current draw na kiya ja raha ho. Is condition ko cell ka Electromotive Force (EMF) kaha jata hai.
The potential difference between two points in a current-carrying conductor is defined as the work done to move a unit charge from one point to the other. What is the alternative dimensional configuration of its SI unit, the Volt (V)?
धारावाही चालक में दो बिंदुओं के बीच विभवांतर को एक बिंदु से दूसरे बिंदु तक इकाई आवेश को ले जाने के लिए किए गए कार्य के रूप में परिभाषित किया जाता है। इसके एसआई (SI) मात्रक वोल्ट (V) का वैकल्पिक आयामी विन्यास क्या है?
(A) 1 V = 1 Joule per Coulomb (1 J/C)
(B) 1 V = 1 Coulomb / 1 Second
(C) 1 V = 1 Newton meter per Ampere
(D) 1 V = 1 Watt hour per Second
✅ Answer & Explanation
Sahi jawab: A) 1 V = 1 Joule per Coulomb (1 J/C)Explanation: Potential difference ka formula hota hai V = W / Q (Work done / Charge). Isliye 1 Volt = 1 Joule / 1 Coulomb (1 J C^-1) hota hai.
A voltmeter is an instrument deployed to track the electric potential difference between two specific points in a circuit. To accomplish this, how must it be geometrically configured relative to those points?
एक वोल्टमीटर एक ऐसा उपकरण है जिसे सर्किट में दो विशिष्ट बिंदुओं के बीच विद्युत विभवांतर को मापने के लिए तैनात किया जाता है। इसे प्राप्त करने के लिए, इसे उन बिंदुओं के सापेक्ष ज्यामितीय रूप से कैसे कॉन्फ़िगर किया जाना चाहिए?
(A) It must be connected in series directly into the main loop track.
(B) It must be wrapped as a non-conducting shield around the resistor substrate.
(C) It is always connected in parallel across the points between which the potential difference is to be measured.
(D) It is connected in series only when the total resistance tends to infinity.
✅ Answer & Explanation
Sahi jawab: C) It is always connected in parallel across the points between which the potential difference is to be measured.Explanation: Voltmeter ko hamesha component ke parallel me connect karte hain taaki dono points ke beech ka exact potential drop measure kiya ja sake. Iska internal resistance bahut high (ideally infinite) hota hai taaki ye main line se current na kheenche.
Ohm’s law states that the potential difference across the ends of a metallic resistor is directly proportional to the current traversing it. What primary ambient physical condition must be kept strictly constant for this proportionality to remain valid?
ओह्म का नियम बताता है कि एक धात्विक प्रतिरोधक के सिरों पर विभवांतर इसके माध्यम से गुजरने वाली धारा के सीधे समानुपाती होता है। इस समानुपात के मान्य रहने के लिए किस प्राथमिक परिवेशी भौतिक स्थिति को कड़ाई से स्थिर रखा जाना चाहिए?
(A) The total length of the connecting wire loop.
(B) The temperature of the conductor must remain the same.
(C) The cross-sectional base area of the target resistor.
(D) The absolute atmospheric pressure surrounding the circuit matrix.
✅ Answer & Explanation
Sahi jawab: B) The temperature of the conductor must remain the same.Explanation: Ohm's Law (V proportional to I) tabhi valid rehta hai jab conductor ka temperature constant rahe, kyunki temperature change hone par conductor ka resistance badal jata hai.
The resistance (R) of a uniform material conductor is dictated by its structural dimensions. According to electro-physics laws, the resistance depends:
एक समान सामग्री के चालक का प्रतिरोध (R) उसकी संरचनात्मक विमाओं (dimensions) द्वारा तय होता है। विद्युत-भौतिकी के नियमों के अनुसार, प्रतिरोध किस पर निर्भर करता है?
(A) Directly on its cross-sectional area and inversely on its length parameter.
(B) Symmetrically on the square of both its length and area vectors.
(C) Exclusively on the time duration for which the current is maintained.
(D) Directly on its length, inversely on its area of cross-section, and on the nature of the material.
✅ Answer & Explanation
Sahi jawab: D) Directly on its length, inversely on its area of cross-section, and on the nature of the material.Explanation: Formula R = rho * (l / A) hota hai. Iska matlab resistance length ke directly proportional, cross-sectional area ke inversely proportional aur material ki resistivity (rho) par depend karta hai.
When three resistors R1, R2, and R3 are connected end to end in a series circuit configuration, what parameter remains strictly constant across each individual component?
जब तीन प्रतिरोधक R1, R2, और R3 एक श्रेणी सर्किट (series circuit) विन्यास में एक छोर से दूसरे छोर तक जुड़े होते हैं, तो प्रत्येक व्यक्तिगत घटक पर कौन सा पैरामीटर कड़ाई से स्थिर रहता है?
(A) The electric current passing through each resistor is exactly the same.
(B) The potential difference across each resistor is identical.
(C) The total power dissipated by each substrate vanishes symmetrically.
(D) The resistivity factor varies inversely with the position index.
✅ Answer & Explanation
Sahi jawab: A) The electric current passing through each resistor is exactly the same.Explanation: Series circuit me current ke flow hone ke liye sirf ek single path hota hai, isliye circuit ke har resistor se bilkul same current (I) flow hota hai.
When multiple resistors are connected end to end in series, the total potential difference (V) across the combination relates to individual component potential differences as:
जब कई प्रतिरोधक श्रेणी में एक छोर से दूसरे छोर तक जुड़े होते हैं, तो संयोजन पर कुल विभवांतर (V) व्यक्तिगत घटक विभवांतरों से किस प्रकार संबंधित होता है?
(A) The total potential difference is the geometric mean of components.
(B) The net potential difference drops to zero to maintain charge conservation.
(C) The total potential difference is equal to the sum of potential differences across the individual resistors (V = V1 + V2 + V3).
(D) The total value varies inversely with the equivalent resistance parameter.
✅ Answer & Explanation
Sahi jawab: C) The total potential difference is equal to the sum of potential differences across the individual resistors (V = V1 + V2 + V3).Explanation: Series connection me total voltage sabhi components me divide ho jata hai, isliye source ka total potential difference V sabhi individual drops ke sum ke barabar hota hai (V = V1 + V2 + V3).
Why is it practically impossible or highly impracticable to connect an electric lighting bulb and a high-power electric room heater in a single series circuit loop?
एक सिंगल श्रेणी सर्किट (series circuit) लूप में एक इलेक्ट्रिक लाइटिंग बल्ब और एक हाई-पावर इलेक्ट्रिक रूम हीटर को जोड़ना व्यावहारिक रूप से असंभव या अत्यधिक अव्यावहारिक क्यों है?
(A) Because the series connection causes an immediate short circuit at the cell terminals.
(B) Because they require electric currents of widely different values to operate properly, which a series circuit cannot provide since current is constant.
(C) Because the series configuration transforms the voltage into an alternating current mode.
(D) Because the combined resistivity of the alloy matrix drops to absolute zero.
✅ Answer & Explanation
Sahi jawab: B) Because they require electric currents of widely different values to operate properly, which a series circuit cannot provide since current is constant.Explanation: Bulb ko kam current chahiye hota hai jabki room heater ko heat produce karne ke liye bahut high current ki zaroorat hoti hai. Series me connect karne se dono ko same current milega, jisse dono me se koi bhi theek se kaam nahi karega.
What is a major structural disadvantage of using a series circuit configuration for domestic appliances in household wiring?
घरेलू तारों में घरेलू उपकरणों के लिए श्रेणी सर्किट विन्यास (series circuit configuration) का उपयोग करने का एक प्रमुख संरचनात्मक नुकसान क्या है?
(A) When one component fails, the circuit is broken anywhere and none of the other components work.
(B) The total equivalent resistance drops too low, drawing dangerous currents.
(C) The series configuration reverses the charge vectors randomly over time.
(D) The total power consumed becomes strictly independent of the number of appliances.
✅ Answer & Explanation
Sahi jawab: A) When one component fails, the circuit is broken anywhere and none of the other components work.Explanation: Series wiring me agar ek appliance kharab ya off ho jaye, toh circuit wahi par break ho jata hai aur baaki saare devices bhi turant band ho jaate hain.
In a parallel circuit configuration, several resistors are connected simultaneously across two common nodes. What parameter remains identical across all these parallel branches?
एक समानांतर सर्किट विन्यास (parallel circuit configuration) में, कई प्रतिरोधक दो सामान्य नोड्स पर एक साथ जुड़े होते हैं। इन सभी समानांतर शाखाओं में कौन सा पैरामीटर समान रहता है?
(A) The current traversing each separate branch is identical.
(B) The individual power dissipation factor scales linearly with the resistance.
(C) The electric potential difference across its ends is the same for all resistors.
(D) The net equivalent resistance becomes the sum of individual blocks.
✅ Answer & Explanation
Sahi jawab: C) The electric potential difference across its ends is the same for all resistors.Explanation: Parallel circuit me saare components direct do common points ke beech jude hote hain, isliye har branch ke cross voltage (potential difference) hamesha same rehta hai.
When multiple electrical gadgets with widely different internal resistances are connected in a parallel configuration, the net total resistance (Rp) of the system:
जब व्यापक रूप से भिन्न आंतरिक प्रतिरोधों वाले कई विद्युत उपकरणों को एक समानांतर विन्यास में जोड़ा जाता है, तो प्रणाली का नेट कुल प्रतिरोध (Rp):
(A) Increases significantly beyond the highest resistance value connected.
(B) Stays completely equal to the algebraic average of the component vectors.
(C) Becomes independent of the material composition parameters of the conductors.
(D) Is decreased according to the reciprocal relation 1/Rp = 1/R1 + 1/R2 + 1/R3, making it smaller than the smallest individual resistance.
✅ Answer & Explanation
Sahi jawab: D) Is decreased according to the reciprocal relation 1/Rp = 1/R1 + 1/R2 + 1/R3, making it smaller than the smallest individual resistance.Explanation: Parallel formula 1/Rp = 1/R1 + 1/R2 + ... ke mutabiq, equivalent resistance system ke sabse chhote resistance value se bhi kam ho jata hai.
When an electric current is maintained continuously through a purely resistive circuit configuration consisting of resistors only connected to a battery, what happens to the electrical energy expended by the source?
जब एक बैटरी से जुड़े केवल प्रतिरोधकों वाले विशुद्ध रूप से प्रतिरोधी सर्किट विन्यास (purely resistive circuit configuration) के माध्यम से लगातार विद्युत धारा बनाए रखी जाती है, तो स्रोत द्वारा खर्च की गई विद्युत ऊर्जा का क्या होता है?
(A) The energy is stored permanently as electro-chemical potential inside the resistor matrix.
(B) The source energy continually gets dissipated entirely in the form of heat.
(C) The energy transforms into non-zero mass cosmic particle fields.
(D) The energy collapses into an imaginary field vector normal to the loop plane.
✅ Answer & Explanation
Sahi jawab: B) The source energy continually gets dissipated entirely in the form of heat.Explanation: Resistive circuit me koi mechanical kaam (jaise motor ghumna) nahi hota, isliye source ki saari electrical energy resistors ke collision ki wajah se heat ke roop me dissipate ho jati hai.
Joule’s law of heating defines the heat (H) generated in a conductor of resistance R carrying a current I for a time duration t as H = I^2*R*t. This law mathematically implies that for a given fixed resistance, the heat produced is directly proportional to:
जूल के तापन का नियम (H = I^2*R*t) प्रतिरोध R के चालक में समय अवधि t के लिए धारा I प्रवाहित होने पर उत्पन्न ऊष्मा (H) को परिभाषित करता है। यह नियम गणितीय रूप से दर्शाता है कि एक निश्चित प्रतिरोध के लिए उत्पन्न ऊष्मा किसके सीधे समानुपाती होती है?
(A) The square of the electric current (I^2).
(B) The square root of the electric potential difference.
(C) The linear inverse of the elapsed time coordinate.
(D) The total macroscopic mass of the metallic core wire.
✅ Answer & Explanation
Sahi jawab: A) The square of the electric current (I^2).Explanation: Formula H = I^2*R*t ke mutabiq, agar resistance R aur time t constant hain, toh heat current ke square (I^2) ke directly proportional hoti hai.
In a standard electric incandescent light bulb, the filament must get extremely hot to emit visible light without melting. What strong metal is deployed for making bulb filaments, and what is its approximate melting point?
एक मानक तापदीप्त (incandescent) विद्युत बल्ब में, फिलामेंट को बिना पिघले दृश्य प्रकाश उत्सर्जित करने के लिए अत्यधिक गर्म होना चाहिए। बल्ब फिलामेंट बनाने के लिए किस मजबूत धातु का उपयोग किया जाता है, और इसका अनुमानित गलनांक (melting point) क्या है?
(A) Copper, with a melting point of 1085 degrees C.
(B) Aluminium, with a melting point of 660 degrees C.
(C) Tungsten, with an extremely high melting point of 3380 degrees C.
(D) Lead-tin alloy, with a low melting point of 183 degrees C.
✅ Answer & Explanation
Sahi jawab: C) Tungsten, with an extremely high melting point of 3380 degrees C.Explanation: Tungsten ka melting point bohot high (lagbhag 3380 C) hota hai aur iski mechanical strength achhi hoti hai. Is wajah se ye bina pighle high temperature par glow karke light generate kar sakta hai.
To prolong the operating lifespan of the high-temperature filament inside an electric light bulb, the glass shell is evacuated and usually back-filled with which chemically inactive gases?
एक विद्युत प्रकाश बल्ब के भीतर उच्च तापमान वाले फिलामेंट के परिचालन जीवनकाल को बढ़ाने के लिए, कांच के आवरण को खाली किया जाता है और आमतौर पर किन रासायनिक रूप से निष्क्रिय गैसों से भरा जाता है?
(A) Chemically inactive nitrogen and argon gases.
(B) Pure highly reactive Oxygen and Hydrogen gas mixtures.
(C) Carbon dioxide and carbon monoxide trace elements.
(D) Chlorine and fluorine active halogen vapours.
✅ Answer & Explanation
Sahi jawab: A) Chemically inactive nitrogen and argon gases.Explanation: Agar bulb me oxygen hogi toh high temperature par tungsten ka oxidation ho jayega aur filament jal jayega. Isko rokne ke liye bulb me chemically inactive gases jaise Nitrogen ya Argon bhari jati hain.
An electric safety fuse protects household circuits and delicate appliances from dangerously high currents. According to physics layouts, how is the fuse placed relative to the device it protects?
एक विद्युत सुरक्षा फ्यूज (electric safety fuse) घरेलू सर्किट और नाजुक उपकरणों को खतरनाक रूप से उच्च धाराओं से बचाता है। भौतिकी के अनुसार, फ्यूज को उस उपकरण के सापेक्ष कैसे रखा जाता है जिसकी वह सुरक्षा करता है?
(A) The fuse is always connected in parallel across the device.
(B) The fuse is mounted as an isolated external ground plane.
(C) The fuse configuration is randomized depending on the building area.
(D) The fuse is placed in series with the device.
✅ Answer & Explanation
Sahi jawab: D) The fuse is placed in series with the device.Explanation: Fuse ko hamesha live wire ke sath series me lagaya jata hai taaki agar circuit me rated limit se zyada current aaye, toh fuse wire pehle hi pighal kar circuit ko cut-off kar de.
What occurs physically to a safety fuse wire when an abnormally high electric current, exceeding its rated specified value, passes through the circuit loop?
जब सर्किट लूप के माध्यम से एक असामान्य रूप से उच्च विद्युत धारा, जो इसके निर्धारित निर्दिष्ट मान से अधिक है, गुजरती है, तो सुरक्षा फ्यूज तार के साथ भौतिक रूप से क्या होता है?
(A) Its resistance drops to zero, allowing the high current to pass safely.
(B) The temperature of the fuse wire increases due to Joule heating, melting the wire and breaking the circuit open.
(C) The fuse wire undergoes mechanical polarization, transforming into a magnet.
(D) The fuse wire expands its cross-sectional area to accommodate the charge flux.
✅ Answer & Explanation
Sahi jawab: B) The temperature of the fuse wire increases due to Joule heating, melting the wire and breaking the circuit open.Explanation: Excessive current flow hone par Joule heating (H = I^2*R*t) ki wajah se fuse wire tezi se garam ho jata hai. Low melting point hone ke karan ye pighal jata hai aur circuit safely break ho jata hai.
The SI unit of electric power (P) is the Watt (W). According to electro-physics metrics, one Watt of power is consumed by a device when:
विद्युत शक्ति (P) का एसआई (SI) मात्रक वाट (W) है। विद्युत-भौतिकी के मानदंडों के अनुसार, किसी उपकरण द्वारा एक वाट शक्ति की खपत तब की जाती है जब:
(A) It carries 1 Coulomb of charge operating for a duration of 1 Hour.
(B) Its internal resistance equals exactly 1 Ohm at absolute zero temperature.
(C) It carries 1 A of current when operated at a potential difference of 1 V (1 W = 1 V * 1 A).
(D) The total heat energy dissipated scales to 3.6 * 10^6 Joules.
✅ Answer & Explanation
Sahi jawab: C) It carries 1 A of current when operated at a potential difference of 1 V (1 W = 1 V * 1 A).Explanation: Electric power ka formula P = V * I hota hai. Jab 1 Volt ke potential difference par 1 Ampere ka current flow hota hai, toh power consumption 1 Watt (1 W = 1 V * 1 A) kehlati hai.
The unit 'Watt' is extremely small for industrial and commercial billing tracking. What is the standard commercial unit of electrical energy commonly known as a 'unit'?
औद्योगिक और व्यावसायिक बिलिंग ट्रैकिंग के लिए 'वाट' मात्रक अत्यंत छोटा है। विद्युत ऊर्जा का मानक व्यावसायिक मात्रक क्या है जिसे आमतौर पर 'यूनिट' (unit) कहा जाता है?
(A) The kilowatt hour (kWh).
(B) The Volt-Ampere second (V A s).
(C) The Joule per second (J/s).
(D) The Ampere hour rating field.
✅ Answer & Explanation
Sahi jawab: A) The kilowatt hour (kWh).Explanation: Bijli ke commercial consumption ko napne ke liye Kilowatt-hour (kWh) ka use kiya jata hai. 1 kWh ka matlab 1000 Watts ka load 1 ghante tak continuous chalna hota hai. Isi ko 1 Unit bijli bolte hain.
When evaluating the commercial electrical energy consumption conversion, one kilowatt-hour (1 kWh) corresponds precisely to how many Joules (J) of energy?
व्यावसायिक विद्युत ऊर्जा खपत रूपांतरण का मूल्यांकन करते समय, एक किलोवाट-घंटा (1 kWh) सटीक रूप से कितने जूल (J) ऊर्जा के बराबर होता है?
(A) 1 kWh = 1000 J
(B) 1 kWh = 220 J
(C) 1 kWh = 3.6 * 10^6 Joules (3,600,000 J)
(D) 1 kWh = 1.6 * 10^-19 J
✅ Answer & Explanation
Sahi jawab: C) 1 kWh = 3.6 * 10^6 Joules (3,600,000 J)Explanation: 1 kWh = 1000 W * 3600 seconds = 3,600,000 Joules = 3.6 * 10^6 J hota hai.
A widespread misconception among consumers is that electrons are consumed or used up when an appliance operates in an electric circuit. What is the actual physical fact regarding what we pay the electricity company for?
उपभोक्ताओं के बीच एक व्यापक गलत धारणा यह है कि जब कोई उपकरण इलेक्ट्रिक सर्किट में काम करता है तो इलेक्ट्रॉन समाप्त या उपभोग हो जाते हैं। हम बिजली कंपनी को वास्तव में किस चीज के लिए भुगतान करते हैं, इसके संबंध में वास्तविक भौतिक तथ्य क्या है?
(A) We pay for the mass weight of new electrons injected into the appliance.
(B) We pay for the static magnetic charge fields accumulated inside the house walls.
(C) We pay for the oxidation transformation of the copper wire atoms.
(D) We pay for the energy used to move electrons through the electric gadgets like electric bulb, fan and engines.
✅ Answer & Explanation
Sahi jawab: D) We pay for the energy used to move electrons through the electric gadgets like electric bulb, fan and engines.Explanation: Circuit me electrons kabhi khatam ya consume nahi hote, wo sirf loop me move karte hain. Hum bijli company ko electrons ko push aur move karne wali energy (work done) ka bill dete hain.
The metric unit of electric charge is the Coulomb (C). According to physics standards, one Coulomb of charge is equivalent to the collective charge contained in approximately how many electrons?
विद्युत आवेश का मात्रक कूलॉम (C) है। भौतिकी के मानकों के अनुसार, एक कूलॉम आवेश लगभग कितने इलेक्ट्रॉनों में निहित सामूहिक आवेश के बराबर होता है?
(A) Nearly 1.6 * 10^-19 electrons.
(B) Nearly 6 * 10^18 electrons.
(C) Exactly 1000 electrons per cubic meter.
(D) An infinite number of electrons.
✅ Answer & Explanation
Sahi jawab: B) Nearly 6 * 10^18 electrons.Explanation: Ek electron par charge e = 1.6 * 10^-19 C hota hai. Isliye 1 Coulomb charge banne ke liye total electrons n = Q / e = 1 / (1.6 * 10^-19) lagbhag 6.25 * 10^18 electrons ki zaroorat hoti hai.
A metallic conductor has a uniform structural resistance (R). If this conductor is stretched uniformly to double its original length while keeping its material mass constant, what happens to its resistance?
एक धात्विक चालक का एकसमान संरचनात्मक प्रतिरोध (R) होता है। यदि इस चालक को इसकी सामग्री के द्रव्यमान को स्थिर रखते हुए इसकी मूल लंबाई से दोगुना समान रूप से खींचा जाता है, तो इसके प्रतिरोध का क्या होता है?
(A) The resistance increases to four times its original value (4R).
(B) The resistance stays completely identical at R.
(C) The resistance decreases precisely to one-half (R/2).
(D) The resistivity factor collapses to absolute zero dynamically.
✅ Answer & Explanation
Sahi jawab: A) The resistance increases to four times its original value (4R).Explanation: Jab taar ko khinch kar length double (2L) ki jati hai, toh volume constant rakhne ke liye uska cross-sectional area aadha (A/2) ho jata hai. Formula R = rho * (L/A) ke according new resistance 4 guna (4R) ho jata hai.
What is the standard 'Voltage' and 'Frequency' of domestic AC power in Indian households?
भारतीय घरों में घरेलू एसी बिजली का मानक 'वोल्टेज' और 'आवृत्ति' क्या है?
(A) 110V, 60Hz
(B) 440V, 50Hz
(C) 220V, 50Hz
(D) 220V, 60Hz
✅ Answer & Explanation
Sahi jawab: C) 220V, 50HzExplanation: India me domestic power supply 220V (RMS voltage) aur 50Hz frequency standard par operate karti hai.
Which wire in household electrical wiring carries dangerous potential and must have the switch connected to it?
घरेलू विद्युत तारों में कौन सा तार खतरनाक विभव ले जाता है और स्विच को हमेशा किससे जोड़ा जाना चाहिए?
(A) Neutral wire
(B) Earth wire
(C) Ground wire
(D) Phase / Live wire
✅ Answer & Explanation
Sahi jawab: D) Phase / Live wireExplanation: Switch hamesha Live (Phase) wire me lagana zaroori hai. Agar switch off ho aur neutral par laga ho, toh device off hone ke bawjood device ke andar 220V ka high potential bana rahega, jisse shock lagne ka risk hota hai.
What is the primary objective of providing 'Earthing' in household installations?
घरेलू उपकरणों में 'अर्थिंग' (Earthing) प्रदान करने का प्राथमिक उद्देश्य क्या है?
(A) Safety against electric shock
(B) To save electricity consumption
(C) To increase appliance wattage
(D) To stabilize utility frequency
✅ Answer & Explanation
Sahi jawab: A) Safety against electric shockExplanation: Earthing metal body wale appliances me kisi bhi leakage current ko zameen (earth) tak bhejti hai bohot low-resistance path dekar, jisse insaan ko heavy electric shock nahi lagta.
According to the modern international color coding standard for flexible electrical cords, what color is assigned to the 'Neutral' wire?
फ्लेक्सिबल विद्युत तारों के लिए आधुनिक अंतरराष्ट्रीय रंग कोड के अनुसार, 'न्यूट्रल' तार को कौन सा रंग दिया गया है?
(A) Black
(B) Brown
(C) Blue
(D) Green / Yellow
✅ Answer & Explanation
Sahi jawab: C) BlueExplanation: International color code ke mutabiq: Brown wire Live hota hai, Blue wire Neutral hota hai, aur Green/Yellow striped wire Earth hota hai.