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Saturday, 16 September 2017

Current Electricity - MCQs

Current Electricity - MCQs Points : Current Electricity, mcqs, Current Electricity fill in the blanks, mechanics objective type questions 1. The specific resistance of all metals is most affected by
(a) applied magnetic field
(b) illumination
(c) pressure
(d) temperature

2. Through a metallic conductor an electric current is passed due to the drift of
(a) protons
(b) neutrons
(c) +ve ions
(d) free electrons

3. Through an electrolyte an electric current is passed due to the drift of
(a) protons
(b) free electrons
(c) + ye and -ye ions
(d) free electrons and holes

Saturday, 5 August 2017

Electrostatics - MCQs

Electrostatics - MCQs Points : Electrostatics, - mcqs, Heat and Thermodynamics fill in the blanks, mechanics objective type questions 1. Objects may acquire an excess or deficiency of free electrons by
(a) grinding
(b) shielding
(c) grounding
(d) rubbing

2. The electric charge in uniform motion produces
(a) both electric and magnetic fields
(b) neither electric nor magnetic field
(c) a magnetic field only
(d) an electric field only

3. Which of the following is a semi-conductor?
(a) Gold
(b) Aluminum
(c) Germanium
(d) Glass

Monday, 19 June 2017

Optics - MCQs

Optics - MCQs Points : optics mcqs, optics fill in the blanks, optics objective type questions 1. A lamp is hanging at a height 40 cm from the centre of a table. If its height is increased by 10 cm the illuminance on the table will decrease by
(a) 10%
(b) 20%
(c) 27%
(d) 36%

2. Inverse square law for illuminance is valid for
(a) isotropic point source
(b) acylindrical source
(c) a search light
(d) all types of sources

3. In a movie hail, the distance between the projector and the screen is increased by 1%. The illumination on the screen is
(a) increased by 1%
(b) descreased by 1%
(c) increased by 2%
(d) decreased by 2%

Thursday, 4 May 2017

Sound - MCQs

Sound - MCQs Points :sound mcqs, mechanics fill in the blanks, mechanics objective type questions 1. It is possible to distinguish between transverse and longitudinal waves by studying the property of
(a) interference
(b) diffraction
(c) reflection
(d) polarization

2. In a mechanical transverse wave, the particles of the medium
(a) vibrate in a direction perpendicular to the direction of propagation
(b) vibrate in a direction parallel to the direction of propagation
(c) move in circles
(d) move in ellipses

3. When a sound wave goes from one medium to another, the quantity that remains unchanged is
(a) speed
(b) amplitude
(c) frequency
(d) wavelength

Tuesday, 18 April 2017

Heat and Thermodynamics - MCQs

Heat and Thermodynamics - MCQs Points : Heat and Thermodynamics - mcqs, Heat and Thermodynamics fill in the blanks, mechanics objective type questions 1. Temperature of a block of iron is 140°F. Its temperature on the celsius scale will be
(a) 20°
(b) 40°
(c) 60°
(d) 80°

2. In the equation PV=RT, V stands for the volume of
(a) 1 litre of gas
(b) one gram of gas
(c) any amount of gas
(d) one gm molecules of a gas

3. Ttemperature at which centigrade and Farenheit scales give the similar reading is
(a) 128°C
(b) 32° F
(c) -40°C
(d) -108°C

Monday, 20 March 2017

Mechanics - MCQs

Mechanics - MCQs Points : mechanics - mcqs, mechanics fill in the blanks, mechanics objective type questions 1. Plank’s constant has the dimensions of
(a) energy
(b) work
(c) linear momentum
(d) angular momentum

2. The unit of power is
(a) kilowatt
(b) kilowatt-hour
(c) dyne
(d) joule

3. In the S.I. system, the unit of temperature is
(a) degrees centigrade
(b) kelvin
(c) degrees celsius
(d) degrees fahrenheit

Monday, 6 February 2017

Difference Between Rolling Contact and Sliding Contact Bearing

Difference Between Rolling Contact and Sliding Contact Bearing Points : difference between rolling contact and sliding contact bearing, rolling contact bearing vs sliding contact bearing
Difference Between Rolling Contact and Sliding Contact Bearing
Rolling Contact Bearing
Sliding Contact Bearing
1.Friction coefficient is lower.Friction is great.
2.Easy to sub-micron positioning.Difficult to achieve sub-micron positioning.
3.Easy to estimate lifeDifficult to estimate life

Friday, 3 February 2017

Difference Between Governor and Flywheel

Difference Between Governor and Flywheel Points : difference between governor and flywheel, comparision between governor and flywheel, governor vs flywheel
Difference Between Governor and Flywheel
Governor
Flywheel
1.Valves are there and there opening is controlled by the centrifugal force on the balls attach.There are no valves attached with the flywheel
2.A governor, or a speed limiter, is a device use to calculate and adjust the speed of a machine, such as an engine.The purpose of flywheel is to control speed dissimilarity caused by adjust in turning moment during a cycle.
3.Governor maintains stable mean speed over a period of time.Flywheel controls the speed for one cycle only

Friday, 27 January 2017

Difference between Spur and Helical Gear

Difference between Spur and Helical Gear Points : Difference between Spur Gear and Helical Gear, Spur Gear vs Helical Gear, comparision between Spur Gear and Helical Gear
Difference between Spur and Helical Gear
Spur Gear
Helical Gear
1.These are particularly loud, due to the gear tooth engaging and colliding. Each impact makes loud noises and cause vibration.When two of the teeth start to engage, the contact is gradual--starting at one end of tooth and maintains contact as the gear rotates into full engagement.
2.There are more competent as less teeth touching when two gears are connected.There are less competent because they have more teeth touching when two gears are attached, leading to increased friction.
3.Spur gears are use in screwdrivers, washing machines, windup alarm clocks, and other devices.Helical gears can be used to adjust the rotation angle by 90 deg.

Friday, 20 January 2017

Difference between Soldering and Brazing

Difference between Soldering and Brazing Points : difference between soldering and brazing, comprasion between soldering and brazing, soldering vs brazing
Difference between Soldering and Brazing
Soldering
Brazing
1.Low temperature is sufficient.High temperature is required.
2.Temperature requirement is up to 450°C in soldering joints.Temperature might go to 600°C in brazing joints.
3.Soldered parts are to be clean by water.Brazed parts are to be allowed to cool slowly.

Friday, 6 January 2017

Difference between Semiconductors and Insulators

Difference between Semiconductors and Insulators Points : difference between semiconductors and insulators, comparision between semiconductors and insulators, semiconductors vs insulators
Difference between Semiconductors and Insulators
Semiconductors
Insulators
1.In semiconductor effect of resistance is decrease and effect of temperature is amplify.In insulator effect of resistance is decreases and cause of temperature is increases.
2.They require energy less than insulators and more than good conductors to eliminate an electron from the parent atom.They require extremely large electric field to remove them from the attraction of nucleus.
3.The conductivity of semiconductor is sensible.The conductivity of insulator is very low.

Wednesday, 4 January 2017

Difference between Semiconductors and Conductors

Difference between Semiconductors and Conductors Points : Difference between Semiconductors and Conductors, comparision between Semiconductors and Conductors, Semiconductors vs Conductors
Difference between Semiconductors and Conductors
Semiconductors
Conductors
1.Equally resistivity and contract effects are extremely sensitive to tiny change in physical conditions.Both resistivity and contact effects are extremely sensitive to tiny changes in physical conditions.
2.Moving carrier of electric current are originated due to inclusion of thermal radiant or electric energy as of an external source.Current carriers here are free electrons which exist whether outside energy is functional on not.