Home » UPSC NDA-1 » Which one of the following metals is used in the filaments of photo-el

Which one of the following metals is used in the filaments of photo-el

June 1, 2025 by rawan239

Which one of the following metals is used in the filaments of photo-electric cells that convert light energy into electric energy ?

Tungsten

Copper

Rubidium

Aluminium

This question was previously asked in

UPSC NDA-1 – 2018

Download PDF Attempt Online

Photo-electric cells, which convert light energy into electrical energy via the photoelectric effect, utilize materials with low work functions. Alkali metals are known for their low work functions, meaning they easily emit electrons when illuminated by light of sufficient frequency. Among the given options, Rubidium is an alkali metal and is used in photoemissive surfaces in some types of photocells or photomultiplier tubes. Caesium is also very commonly used, often alloyed with other elements.

Alkali metals have low work functions, making them suitable for use as photoemissive materials in devices that rely on the photoelectric effect.

Tungsten is a refractory metal with a high melting point and is used as a filament in incandescent bulbs, but it has a high work function. Copper and Aluminium are conductors but are not typically used as primary photoemissive surfaces for converting light to electricity in this manner. Photocathodes in modern photomultiplier tubes often use complex alloys or semiconductor materials for optimized sensitivity to different wavelengths of light.

Telangana and Karnataka GK MCQ (2575)

accounting (2134)

Bihar state GK MCQ (1950)

Haryana GK MCQ (1945)

UPSC CAPF (1929)

Economics (1622)

Sentence improvement (1484)

Assam state GK MCQ (1479)

Synonyms (1421)

Jammu and kashmir GK MCQ (1388)

Himachal pradesh GK MCQ (1272)

Kerala state GK MCQ (1225)

Tamilnadu state GK MCQ (1193)

UPSC CISF-AC-EXE (1188)

UPSC IAS (1173)

Preposition (1150)

Financial management (1120)

Gujarat state GK MCQ (1079)

UPSC CDS-2 (1077)

UPSC CDS-1 (1063)

Andhra Pradesh GK MCQ (1043)

Articles (1043)

Arunachal pradesh state GK MCQ (1026)

Manipur GK MCQ (1022)

chemistry (1020)

UPSC NDA-2 (989)

Indian politics (981)

Legal aspects of business (930)

Computer fundamental miscellaneous (918)

Banking and financial institutions (897)

UPSC NDA-1 (892)

sikkim GK MCQ (853)

Environmental Science (811)

Geography (757)

Artificial intelligence (756)

Insurance (752)

Indian railway (726)

Jharkhand GK MCQ (717)

punjab GK MCQ (697)

Building materials (686)

Basic general knowledge (682)

Mizoram GK MCQ (668)

Sentence completion (663)

Meghalaya GK MCQ (618)

Business management (603)

Visual basic (596)

UPSC Geoscientist (594)

Idioms and phrases (589)

Chhattisgarh GK MCQ (565)

Business and commerce (563)

Maharashtra GK MCQ (538)

Spelling check (537)

One word substitution (525)

Waste water engineering (522)

Building construction (508)

Cloud computing (507)

Classification (505)

Surveying (490)

Operating system (476)

Goa GK MCQ (473)

Applied mechanics and graphic statics (468)

Common error detection (457)

Object oriented programming using c plus plus (455)

Ms access (452)

Irrigation engineering (448)

Organic chemistry (432)

Engineering economics (426)

Hydraulics and fluid mechanics (422)

Ordering of sentences (422)

Internet and web technology (377)

Machine learning (371)

Rcc structures design (364)

Madhya Pradesh state GK MCQ (356)

Non metal and its compounds (352)

UPSC Combined Section Officer (351)

Odisha GK MCQ (349)

Selecting words (342)

Teaching and research (322)

Management information systems (321)

Chemistry in everyday life (296)

Days and years (293)

World geography (290)

Nagaland GK MCQ (289)

Sentence formation (278)

Construction planning and management (276)

Computer Hardware (270)

Power point (262)

Data science miscellaneous (260)

Direct and indirect speech (255)

Odd man out (254)

Books and authors (252)

Environmental engineering (252)

System analysis and design (234)

Famous personalities (230)

Statement and assumption (230)

UPSC SO-Steno (227)

Ecommerce (226)

Highway engineering (218)

Ordering of words (217)

World organisations (214)

Automation system (204)

Concrete technology and design of concrete structures (200)

Electronic principles (195)

Soil mechanics and foundation (194)

Jainism and buddhism (191)

Airport engineering (184)

Embedded systems (183)

Design of steel structures (182)

Railway engineering (182)

Internet of things (iot) (181)

Hrm in commerce (181)

Indian culture (176)

Electrical machine design (175)

technology (172)

Indian Polity (172)

Disk operating system (dos) (169)

Digital computer electronics (168)

Medieval history art and culture (166)

Theory of structures (162)

agriculture (161)

Vlsi design and testing (161)

Awards and honours (146)

Wireless Communication (143)

Linear Algebra (137)

Statement and arguments (132)

Data analysis with python (130)

Css properties, css elements, css functions and tables (129)

Indian Economy (124)

Transformers (123)

UPSC CBI DSP LDCE (119)

General science (116)

Css text, borders and images (115)

Signal processing (114)

Database systems (112)

Blood relation (111)

Electrostatics (106)

Bhakti movement (105)

D.c. Generators (105)

Indian history (103)

Introduction to data science (102)

D.c. Motors (101)

Missing character finding (100)

Current Affairs (99)

Single phase induction motors (99)

Economics of power generation (99)

Synchronous motors (99)

Series completion (99)

Electrolysis and storage of batteries (98)

General Knowledge (98)

Electronics and instrumentation (97)

Business finance (97)

Transistors (96)

Transmission and distribution (95)

A.c fundamentals, circuits and circuit theory (95)

Missing number finding (95)

Statement and conclusion (94)

Switchgear protections (94)

Electrical control systems (93)

Machine learning algorithms (92)

Course of action (91)

Information theory and coding (90)

Current electricity (89)

Basics of organic reaction mechanism (89)

Business statistics and research methods (89)

Logical deduction (87)

Business environment and international business (87)

Data collection and preprocessing (87)

Optical communication (81)

Number series completion (80)

Probability and statistics (72)

government (68)

Literature (68)

Indian Constitution (61)

environment (53)

statistics (49)

population (41)

mathematics (40)

Computer Science (40)

Ancient history art and culture (32)

Constitutional Law (31)

Demography (28)

arithmetic (28)

Science and Technology (21)

international relations (17)

International Law (17)

Archaeology (13)

Earth Science (13)

Islamic Law (12)

electricity (11)

Exit mobile version