Consider the following statements regarding LED lighting in industrial environments:
1. LEDs have higher luminous efficacy compared to High-Pressure Mercury Vapor lamps.
2. They offer a longer operational life, typically exceeding 50,000 hours.
3. The Color Rendering Index (CRI) of LEDs is generally poor for detailed industrial inspection tasks.
Which of the statements given above is/are correct?
Answer & step-by-step solution
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. Suitable luminaires can also provide high CRI, so poor color rendering is not an inherent LED limitation; inspection areas can be designed with high-CRI LED sources. Key relation: Luminous efficacy=lumens/electrical watt.
Exam focus: Check efficacy, lifetime, CRI and glare together. Common trap: LED does not automatically mean poor CRI.
Statement-wise Verification
- Statement 1 - Correct.
LEDs have higher luminous efficacy compared to High-Pressure Mercury Vapor lamps.
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. - Statement 2 - Correct.
They offer a longer operational life, typically exceeding 50,000 hours.
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. - Statement 3 - Incorrect.
The Color Rendering Index (CRI) of LEDs is generally poor for detailed industrial inspection tasks.
The correct principle is: Suitable luminaires can also provide high CRI, so poor color rendering is not an inherent LED limitation; inspection areas can be designed with high-CRI LED sources.
Core Concept
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. Suitable luminaires can also provide high CRI, so poor color rendering is not an inherent LED limitation; inspection areas can be designed with high-CRI LED sources.
Formula / Key Relationship
Luminous efficacy=lumens/electrical watt.
Why the Other Options Are Wrong
Option A is incorrect because it includes incorrect statement(s) 3. Option B is incorrect because it includes incorrect statement(s) 3 and omits correct statement(s) 1. Option C is incorrect because it includes incorrect statement(s) 3 and omits correct statement(s) 2.
Exam Shortcut / Approach
Check efficacy, lifetime, CRI and glare together.
Common Mistake
LED does not automatically mean poor CRI.
Quick Revision
Efficacy Lifetime and CRI is linked with LED Lighting, Lighting and Industrial Electrical Systems. Check efficacy, lifetime, CRI and glare together.
औद्योगिक वातावरण में LED प्रकाश के संबंध में निम्नलिखित कथनों पर विचार कीजिए:
1. उच्च-दबाव मर्करी वेपर लैंप की तुलना में LED की दीप्त दक्षता (luminous efficacy) अधिक होती है।
2. ये लंबा संचालन जीवन देते हैं, सामान्यतः 50,000 घंटे से अधिक।
3. विस्तृत औद्योगिक निरीक्षण कार्यों के लिए LED का कलर रेंडरिंग इंडेक्स (CRI) सामान्यतः खराब होता है।
ऊपर दिए गए कथनों में से कौन-सा/से सही है/हैं?
उत्तर और चरणबद्ध हल
D — केवल 1 और 2। आधुनिक औद्योगिक LED मर्करी वेपर की तुलना में अधिक lm/W और लंबा जीवन देते हैं। उपयुक्त LED उच्च CRI भी दे सकते हैं, इसलिए खराब CRI LED की अंतर्निहित सीमा नहीं है।
विस्तृत हल (मूल भाषा में)
Statement-wise Verification
- Statement 1 - Correct.
LEDs have higher luminous efficacy compared to High-Pressure Mercury Vapor lamps.
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. - Statement 2 - Correct.
They offer a longer operational life, typically exceeding 50,000 hours.
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. - Statement 3 - Incorrect.
The Color Rendering Index (CRI) of LEDs is generally poor for detailed industrial inspection tasks.
The correct principle is: Suitable luminaires can also provide high CRI, so poor color rendering is not an inherent LED limitation; inspection areas can be designed with high-CRI LED sources.
Core Concept
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. Suitable luminaires can also provide high CRI, so poor color rendering is not an inherent LED limitation; inspection areas can be designed with high-CRI LED sources.
Formula / Key Relationship
Luminous efficacy=lumens/electrical watt.
Why the Other Options Are Wrong
Option A is incorrect because it includes incorrect statement(s) 3. Option B is incorrect because it includes incorrect statement(s) 3 and omits correct statement(s) 1. Option C is incorrect because it includes incorrect statement(s) 3 and omits correct statement(s) 2.
Exam Shortcut / Approach
Check efficacy, lifetime, CRI and glare together.
Common Mistake
LED does not automatically mean poor CRI.
Quick Revision
Efficacy Lifetime and CRI is linked with LED Lighting, Lighting and Industrial Electrical Systems. Check efficacy, lifetime, CRI and glare together.
ઔદ્યોગિક વાતાવરણમાં LED લાઇટિંગ અંગે નીચેનાં વિધાનો ધ્યાનમાં લો:
1. ઊંચા-દબાણના મર્ક્યુરી વેપર લેમ્પ કરતાં LEDની પ્રકાશ કાર્યક્ષમતા (luminous efficacy) વધુ હોય છે.
2. તે લાંબું સંચાલન આયુષ્ય આપે છે, સામાન્ય રીતે 50,000 કલાકથી વધુ.
3. વિગતવાર ઔદ્યોગિક નિરીક્ષણ કાર્યો માટે LEDનો કલર રેન્ડરિંગ ઇન્ડેક્સ (CRI) સામાન્ય રીતે નબળો હોય છે.
ઉપર આપેલાં વિધાનોમાંથી કયું/કયાં સાચું/સાચાં છે?
જવાબ અને પગલાવાર ઉકેલ
D — ફક્ત 1 અને 2. આધુનિક ઔદ્યોગિક LED મર્ક્યુરી વેપર કરતાં વધુ lm/W અને લાંબું આયુષ્ય આપે છે. યોગ્ય LED ઊંચો CRI પણ આપી શકે છે, તેથી નબળો CRI LEDની સ્વાભાવિક મર્યાદા નથી.
વિગતવાર ઉકેલ (મૂળ ભાષામાં)
Statement-wise Verification
- Statement 1 - Correct.
LEDs have higher luminous efficacy compared to High-Pressure Mercury Vapor lamps.
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. - Statement 2 - Correct.
They offer a longer operational life, typically exceeding 50,000 hours.
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. - Statement 3 - Incorrect.
The Color Rendering Index (CRI) of LEDs is generally poor for detailed industrial inspection tasks.
The correct principle is: Suitable luminaires can also provide high CRI, so poor color rendering is not an inherent LED limitation; inspection areas can be designed with high-CRI LED sources.
Core Concept
Modern industrial LEDs provide high luminous efficacy and long service life compared with older mercury-vapor technology. Suitable luminaires can also provide high CRI, so poor color rendering is not an inherent LED limitation; inspection areas can be designed with high-CRI LED sources.
Formula / Key Relationship
Luminous efficacy=lumens/electrical watt.
Why the Other Options Are Wrong
Option A is incorrect because it includes incorrect statement(s) 3. Option B is incorrect because it includes incorrect statement(s) 3 and omits correct statement(s) 1. Option C is incorrect because it includes incorrect statement(s) 3 and omits correct statement(s) 2.
Exam Shortcut / Approach
Check efficacy, lifetime, CRI and glare together.
Common Mistake
LED does not automatically mean poor CRI.
Quick Revision
Efficacy Lifetime and CRI is linked with LED Lighting, Lighting and Industrial Electrical Systems. Check efficacy, lifetime, CRI and glare together.
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