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Physical Chemistry

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Among the following electrodes, which one is used in a three electrode electrochemical cell for voltammetric analysis ?

  1. Cellulose electrode

  2. Auxiliary electrode

  3. Hot cathode

  4. Cold cathode


Correct Option: B
Explanation:

The Auxiliary electrode, often called as counter electrode, is used in a three electrode electrochemical cell for voltammetric analysis or other reactions in which an electrical current is expected to flow.

Rectifiers derives DC power from an AC supply. Among the following ---------------------is a type of controlled rectifier .

  1. Thyratron

  2. Krytron

  3. Sprytron

  4. Ignitrons


Correct Option: D
Explanation:

An ignitron is a type of controlled rectifier dating from the 1930's.Ignitrons were long used as high-current rectifiers in major industrial and utility installations where thousands of amperes of AC current must be converted to DC, such as aluminum smelters.

The ----------------------- forming utilises Yutkin effect.

  1. explosive

  2. electro

  3. electrohydraulic

  4. electromagnetic


Correct Option: C
Explanation:

Electrohydraulic forming is a type of metal forming in which an electric arc discharge in liquid (Yutkin effect) is used to convert electrical energy to mechanical energy and change the shape of the workpiece. A capacitor bank delivers a pulse of high current across two electrodes, which are positioned a short distance apart while submerged in a fluid (water or oil).

A coated glass media is used for the projection in

  1. holography

  2. holographic screen

  3. computer generated holography

  4. volumetric display device


Correct Option: B
Explanation:

A holographic screen is a display technology that uses coated glass media for the projection surface of a video projector. Holographic refers to the coating that bundles light using formed microlenses. The lens design and attributes match the holographic area.

Binocular disparity, motion parallax, accommodation and convergence are four eye mechanisms.The display providing these four eye mechanism is

  1. liquid crystal display

  2. electronic visual display

  3. laser lighting display

  4. holographic display


Correct Option: D
Explanation:

Holographic display is a display technology that has the ability to provide all four eye mechanism: binocular disparity, motion parallax, accommodation and convergence. The 3D objects can be viewed without wearing any special glasses and no visual fatigue will be caused to human eyes.

The display elements of various colours are supported by -------------------.

  1. a quantum dot display

  2. a swept-volume display

  3. electroluminescent displays

  4. a vacuum fluorescent display


Correct Option: D
Explanation:

A vacuum fluorescent display (VFD) is a display device used commonly on consumer-electronics equipment such as video cassette recorders, car radios and microwave ovens. VFD emits a very bright light with high contrast and can support display elements of various colours. VFD's can display seven-segment numerals, multi-segment alpha-numeric characters or can be made in a dot-matrix to display different alphanumeric characters and symbols.

Which of the following branches of science applies the principles of physics and materials science?

  1. Biomedical engineering

  2. Chemical engineering

  3. Aerospace engineering

  4. Mechanical engineering


Correct Option: D
Explanation:

Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the design, production, and operation of machines and tools.

'On the Equilibrium of Heterogeneous Substances' is written by

  1. Willard Gibbs

  2. Friedrich Wilhelm Ostwald

  3. William McGuire Bill Bryson

  4. Henri Louis Le Châtelier


Correct Option: A
Explanation:

In the history of thermodynamics, 'On the Equilibrium of Heterogeneous Substances' is a 300-page paper written by American mathematical-engineer Willard Gibbs. It is one of the founding papers in thermodynamics.

Among the following the lowest-energy state is

  1. excited state

  2. quantum state

  3. ground state

  4. stationary state


Correct Option: C
Explanation:

The ground state of a quantum mechanical system is its lowest-energy state; the energy of the ground state is known as the zero-point energy of the system. An excited state is any state with energy greater than the ground state. The ground state of a quantum field theory is usually called the vacuum state or the vacuum.

Among the following energies which one measures the “useful” work obtainable from a closed thermodynamic system ?

  1. Specific surface energy

  2. Helmholtz free energy

  3. Gibbs free energy

  4. Internal energy


Correct Option: B
Explanation:

Helmholtz free energy is a thermodynamic potential which measures the “useful” work obtainable from a closed thermodynamic system at a constant temperature and volume. For such a system, the negative of the difference in the Helmholtz energy is equal to the maximum amount of work extractable from a thermodynamic process in which temperature and volume are held constant.

The amount of heat required to change a substance's temperature by a given amount is termed as

  1. Thermal capacity

  2. Thermal conductivity

  3. Thermal insulation

  4. Thermal radiation


Correct Option: A
Explanation:

Thermal capacity, is the measurable physical quantity that characterizes the amount of heat required to change a substance's temperature by a given amount. In the International System of Units (SI), heat capacity is expressed in units of joule(s) (J) per kelvin (K).

Which of the following is a double working electrode ?

  1. A reference electrode

  2. A reversible hydrogen electrode

  3. A rotating disk electrode

  4. A rotating ring-disk electrode


Correct Option: D
Explanation:

A rotating ring-disk electrode (RRDE) is double working electrode used in hydrodynamic voltammetry, very similar to a rotating disk electrode (RDE). The electrode actually rotates during experiments inducing a flux of analyte to the electrode.

Among the following electrodes --------------------- is used to measure the hydrogen ion concentration.

  1. Gas diffusion electrodes

  2. Fluoride selective electrode

  3. Quinhydrone electrode

  4. Plate electrode


Correct Option: C
Explanation:

The quinhydrone electrode is a type of redox electrode which can be used to measure the hydrogen ion concentration (pH) of a solution in a chemical experiment. It provides an alternative to the commonly used glass electrode in a pH meter.

Carbon dioxide measuring electrode is

  1. The saturated calomel electrode

  2. The Severinghaus electrode

  3. A silver chloride electrode

  4. The standard hydrogen electrode


Correct Option: B
Explanation:

The Severinghaus electrode is an electrode that measures carbon dioxide. It utilizes a CO2-sensitive glass electrode in a surrounding film of bicarbonate solution covered by a thin plastic carbon dioxide permeable membrane, but impermeable to water and electrolytic solutes.

Which of the following metal corrosion takes place in the presence of anoxic water ?

  1. Hydrogen corrosion

  2. Bacterial anaerobic corrosion

  3. Flow-accelerated corrosion

  4. Galvanic corrosion


Correct Option: A
Explanation:

Hydrogen corrosion is a form of metal corrosion occurring in the presence of anoxic water. Hydrogen corrosion involves a redox reaction that reduces hydrogen ions, forming molecular hydrogen.

Which of the following electrodes measures oxygen on a catalytic platinum surface?

  1. The Clark electrode

  2. Working electrode

  3. Liquid metal electrode

  4. Ion-selective electrode (ISE)


Correct Option: A
Explanation:

The Clark electrode is an electrode that measures oxygen on a catalytic platinum surface.

In which of the following corrosions, the boundaries of crystallites of the material are more susceptible to corrosion than their insides?

  1. Intergranular corrosion

  2. Biogenic sulfide corrosion

  3. Hot corrosion

  4. Crevice corrosion


Correct Option: A
Explanation:

Intergranular corrosion (IGC), also known as intergranular attack (IGA), is a form of corrosion where the boundaries of crystallites of the material are more susceptible to corrosion than their insides.

The battery capable of acting as water activated batteries is

  1. The penny battery

  2. A deep-cycle battery

  3. An earth battery

  4. A reserve battery


Correct Option: C
Explanation:

An earth battery is a pair of electrodes made of two dissimilar metals, such as iron and copper, which are buried in the soil or immersed in the sea. Earth batteries act as water activated batteries and if the plates are sufficiently far apart, they can tap telluric currents.

Which of the following batteries does not contain an electrolyte ?

  1. A flow battery

  2. A frog battery

  3. A water-activated battery

  4. Zinc-air batteries


Correct Option: C
Explanation:

A water-activated battery is a disposable reserve battery that does not contain an electrolyte and hence produces no voltage until it is soaked in water for several minutes.

The corrosion applied to both metals and non-metallic materials is

  1. Erosion corrosion

  2. Exfoliation corrosion

  3. Tribocorrosion

  4. Microbial corrosion


Correct Option: D
Explanation:

Microbial corrosion, also called bacterial corrosion, bio-corrosion, microbiologically-influenced corrosion, or microbially-induced corrosion (MIC), is corrosion caused or promoted by microorganisms, usually chemoautotrophs. It can apply to both metals and non-metallic materials.

The unexpected sudden failure of ductile metals due to a tensile stress in a corrosive environment is

  1. corrosion fatigue

  2. stress corrosion cracking

  3. corrosion in space

  4. corrosion monitoring


Correct Option: B
Explanation:

Stress corrosion cracking (SCC) is the unexpected sudden failure of normally ductile metals subjected to a tensile stress in a corrosive environment, especially at elevated temperature in the case of metals.

The fatigue failure of the surface of a material particularly in rolling bearings and gears is known as

  1. red plague

  2. galvanic anode

  3. micro pitting

  4. metal dusting


Correct Option: C
Explanation:

Micro pitting is a fatigue failure of the surface of a material commonly seen in rolling bearings and gears. It is also known as grey staining, micro spalling or frosting.

A wet-chemical cell capable of producing a highly stable voltage is

  1. The Clark cell

  2. An electrochemical cell

  3. Galvanic cell

  4. Commodity cells


Correct Option: A
Explanation:

The Clark cell, is a wet-chemical cell that produces a highly stable voltage usable as a laboratory standard.It uses a zinc, or zinc amalgam, anode and a mercury cathode in a saturated aqueous solution of zinc sulfate, with a paste of mercurous sulfate as depolarizer.

Among the following ---------------------------- is a solution used to test the resistance to corrosion of metals.

  1. Green death

  2. Fougerite

  3. Rusticle

  4. Stalactite


Correct Option: A
Explanation:

Green death is a solution used to test the resistance to corrosion of metals. It consists of 11.9% sulfuric acid, 1.3% hydrochloric acid, 1% Iron(III) chloride and 1% Copper(II) chloride boiling at 103°C.

Among the following cells, which one is suitable as a laboratory standard for calibration of voltmeters?

  1. The Weston cell

  2. The Chromic acid cell

  3. The Bunsen cell

  4. The Grove cell


Correct Option: A
Explanation:

The Weston cell, invented by Edward Weston in 1893, is a wet-chemical cell that produces a highly stable voltage suitable as a laboratory standard for calibration of voltmeters. It was adopted as the International Standard for EMF between 1911 and 1990.

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