Home
Current Affairs January 2024

What is the correct answer?

4

With increase in temperature, the electrical conductivity of semiconductors

A. Increases

B. Decreases

C. Remain constant

D. Either (A) or (B), depends on the type of semi-conductor

Correct Answer :

A. Increases


Related Questions

What is the correct answer?

4

In the blast furnace, incorporation of water vapour in the blast gives the following effect.

A. Increases the reducing potential of the gas

B. Increases the flame temperature

C. No significant change occurs

D. Increases the hydrogen content in the metal

What is the correct answer?

4

Dryness factor of steam is defined as the ratio of the mass of vapor in the mixture to the mass of the mixture. Dryness factor of steam is measured by a __________ calorimeter.

A. Bomb

B. Throttling

C. Junker's

D. Boy's

What is the correct answer?

4

With increase in temperature, the electrical conductivity of semiconductors

A. Increases

B. Decreases

C. Remain constant

D. Either (A) or (B), depends on the type of semi-conductor

What is the correct answer?

4

Oxide layer formed on the non-ferrous metal surface after its annealing is

A. Removed by acid pickling

B. Hammered into the surface

C. Removed with coarse emery cloth

D. Left as such to protect the surface

What is the correct answer?

4

Which of the following test is used for distinguishing among dry oils, semi-drying oils and non drying oils?

A. Elaiden test

B. Reichert-Meissl value test

C. Hunter value test

D. Iodine value test

What is the correct answer?

4

About __________ ton of coke is required in a cupola to produce one ton of casting.

A. 0.03

B. 0.3

C. 0.8

D. 1.5

What is the correct answer?

4

For grinding of softer materials, the grinding wheel should have __________ grain size.

A. Finer

B. Coarser

C. Medium

D. Any type of

What is the correct answer?

4

One ton of refrigeration is not equivalent to the heat removal rate of

A. 200 BTU/minute

B. 50 kcal/minute

C. 50 kJ/sec

D. 3.5 KW

What is the correct answer?

4

Filler material used in welding should have __________ as compared to the parent metal to be welded.

A. Lower melting temperature

B. Same melting temperature

C. Same composition

D. Both 'b' & 'c'

What is the correct answer?

4

The underground well of a biogas plant is called the

A. Septic tank

B. Oxidation well

C. Digestor

D. Lagoon

What is the correct answer?

4

Machinability of hard alloys and tool steels is improved by

A. Spheroidising

B. Annealing

C. Tempering

D. Normalising

What is the correct answer?

4

A material is capable of resisting softening at high temperature, because of its property termed as

A. Hot temper

B. Hot hardness

C. Fatigue

D. Creep

What is the correct answer?

4

Direct conversion of thermal energy to electrical energy is facilitated by the

A. Fuel cells

B. Photo voltaic cell

C. Magneto hydrodynamic generator

D. None of these

What is the correct answer?

4

Heating of ferromagnetic materials to a temperature above Curie temperature makes it

A. Insulator for heat & electricity transmission

B. Ferritic

C. Behave like paramagnetic materials

D. Superconductor

What is the correct answer?

4

A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place

A. The better insulation material should be put just next to pipe (i.e., inside)

B. The better insulating material should be put outside

C. Either of the insulating material could be put on either side

D. Steam temperature is considered before deciding as to which insulating material is to be put inside (i.e., just next to the pipe)

What is the correct answer?

4

__________ joint is mostly used for joining pipes carrying water at low pressure.

A. Nipple

B. Socket

C. Union

D. Bell and spigot

What is the correct answer?

4

The most detrimental impurity in high pressure boiler feed water is

A. Suspended salt

B. Dissolved salt

C. Silica

D. Turbidity

What is the correct answer?

4

For separating small pieces of metal from engine oil of a car, the best separating technique is the

A. Chromatography

B. Evaporation

C. Filtration

D. Fractional distillation

What is the correct answer?

4

LVDT used for displacement measurement is a/an __________ transducer.

A. Passive

B. Active

C. Capacitive

D. None of these

What is the correct answer?

4

The malleability of a material is the property by virtue of which it can be rolled or hammered into thin sheets. Which of the following materials has the maximum malleability?

A. Lead

B. Copper

C. Aluminium

D. Wrought iron

What is the correct answer?

4

Which of the following phenomenon will exhibit the minimum heat transfer?

A. Boiling

B. Forced convection in air

C. Free convection in air

D. Conduction in air

What is the correct answer?

4

Which of the following is not a characteristic observed in material failure by fatigue fracture?

A. Plastic deformation of material does not occur

B. Initiation of crack from below the surface does not occur

C. Initiation of crack occurs on the surface of the machine part

D. Presence of both rough & smooth zone with conchoidal markings in smooth zone of the surface

What is the correct answer?

4

Addition of __________ to steel does not help in improving its machinability.

A. Sulphur

B. Silicon

C. Lead

D. Phosphorous

What is the correct answer?

4

The normal stress is the same in all directions at a point in a fluid, only when the fluid

A. Is at rest & has zero viscosity

B. Is frictionless

C. Fluid layer has no motion relative to an adjacent layer of fluid

D. is incompressible & frictionless

What is the correct answer?

4

Pick out the wrong statement.

A. A soft magnetic material should have high permeability and small area of hysteresis loop

B. Poisson's ratio of high melting point metals is more than unity

C. Solders generally melt at less than 185°C

D. Steel produced by B.O.F process is ideally suited for manufacturing flat product

What is the correct answer?

4

The joint for soldering is supported by binding wire made of

A. Mild steel

B. Copper

C. Soft iron

D. Stainless steel

What is the correct answer?

4

Saturated steam at a pressure of 25 kg/cm2 is throttled to attain 5 kg/cm2. Then the outcoming steam will be

A. Wet

B. Saturated

C. Superheated

D. None of these

What is the correct answer?

4

__________ is used for tying the steel columns to concrete foundation.

A. Grouting

B. Eyebolt

C. Anchor bolts

D. Refractory castables

What is the correct answer?

4

Pick out the wrong statement.

A. A ferromagnetic material becomes paramagnetic above the 'Curie temperature'

B. Permanent magnets are made of hard materials, whereas electromagnets require soft magnetic materials

C. Soft magnetic materials (e.g., pure iron) have higher permeability and low hysterisis loss and coercive forces

D. Tungsten steel and alnico are not hard magnetic materials

What is the correct answer?

4

Faraday's law of electrolysis is related to the

A. Cation speed

B. Atomic number of the cation

C. Equivalent mass of the electrolyte

D. None of these