Description : Black body radiations depends upon a) The shape and nature of the body b) The velocity of radiations and colour of the body c) The temperature of the body d) All of the above
Last Answer : c) The temperature of the body
Description : The emf of a primary cell depends upon the: a) Physical dimension of the cell b) Nature of the electrolyte c) Nature of the electrode d) Both (b) and (c)
Last Answer : Ans: D
Description : The emission of number of photo electrons depends upon a) The colour of the body b) The frequency of incident light c) The intensity of light d) All of the above
Last Answer : c) The intensity of light
Description : Resistance of a super conductor is a. Finite b. Infinite c. Zero d. changes with every conductor
Last Answer : c. Zero
Description : Diffusion co-efficient generally depends upon the temperature, pressure & the nature of the components of the system. Its dimension is not the same as that of the (A) Mass transfer co-efficient (B) Thermal diffusivity (C) Kinematic viscosity (D) Volumetric diffusivity
Last Answer : (A) Mass transfer co-efficient
Description : The current through a metallic conductor is due to the motion of a. free electrons b. Protons c. Neutrons d. still under controversy
Last Answer : a. free electrons
Description : Selenium is: (a) Conductor (b) Insulator in the dark are becomes conductor when exposed to light (c) An insulator (d) None of these
Last Answer : (b) Insulator in the dark are becomes conductor when exposed to light
Description : Select insulating materials for following parts : (i) Insulation between heating element and base plate of electric iron. (ii) Insulation used over copper or aluminium conductor used for making coils. (iii) Transformer bushings. (iv) Insulation between transmission line and pole.
Last Answer : Parts Insulating Materials Insulation between heating element and base plate of electric iron. Mica Insulation used over copper or aluminium conductor used for making coils. ... Transformer bushings Porcelain Insulation between transmission line and pole. Porcelain
Description : When electric current passes through a metallic conductor, its temperature rises. This is due to?
Last Answer : When electric current passes through a metallic conductor, its temperature rises. This is due to collisions between conduction electrons and atoms.
Description : Heat in a conductor is produced on the passage of electric current due to?
Last Answer : Heat in a conductor is produced due to frictional collision of electrons flow as they conduct current.
Description : The electric breakdown strength of insulating materials depends on (A) Nature of applied voltage (B) lmperfection of dielectric material (C) Pressure, temperature and humidity (D) All or these
Last Answer : The electric breakdown strength of insulating materials depends on (A) Nature of applied voltage (B) lmperfection of dielectric material (C) Pressure, temperature and humidity (D) All or these
Description : Reciprocal of resistivity is called a. Resistance b. Inductance c. Conductivity d. Flexibility
Last Answer : c. Conductivity
Description : Find the Norton equivalent resistance for the network shown in Fig No. 2
Last Answer : Solution: To find Norton’s equivalent resistance removing voltage source and current source. Voltage source is replaced by short circuit and current source is replaced by open circuit so, we get circuit as
Description : An a.c series circuit has resistance of 10ohm, inductance of 0.1H and capacitance of 10µf, voltage applied to circuit is 200V. find (i) Resonant frequency (ii) Current at resonance (iii) Power at resonance
Last Answer : Solution: For RLC series circuit
Description : A series combination of resistance 100 ohm and capacitance 50µf is connected in series to a 230 V, 50HZ supply. Calculate (i) Capacitive reactance (ii) Current (iii) Power factor (iv) Power consumed
Last Answer : For RC series circuit
Description : Identify the correct combination of respective Electric arc welding and Electric resistance welding methods : (A) Butt welding and Seam welding (B) Hydrogen shielding and Projection welding (C) Seam welding and Coated electrode welding (D) Coated electrode welding and Hydrogen shielding
Last Answer : Identify the correct combination of respective Electric arc welding and Electric resistance welding methods : (A) Butt welding and Seam welding (B) Hydrogen shielding and Projection welding ... Seam welding and Coated electrode welding (D) Coated electrode welding and Hydrogen shielding
Last Answer : Meggar is an instrument which measures the insulation resistance of an electric circuit relative to earth and one another.
Description : Amount of coal lost in ash particle, which is carried through the boiler system, depends upon the (A) Physical nature, ash content and fineness of the coal (B) Amount of excess air supplied and load on the boiler (C) Type of burner and combustion chamber (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Resistance of an ideal insulator is a. Infinite b. Zero c. Finite d. depends upon nature
Last Answer : a. Infinite
Description : State super position theorem. Write steps to find current in an element using super position theorem.
Last Answer : Statement of superposition theorem: In any linear network containing two or more sources, the current in any element is equal to algebraic sum of the current caused by individual source acting ... . Add algebraically the voltage drops and branch currents to obtain combined effect of all sources.
Description : State maximum power transfer theorem.
Last Answer : The maximum power transfer theorem states that the maximum amount of power will be delivered to the load resistance when the load resistance is equal to the Thevenin/ Norton resistance of the network supplying the power ... draws maximum power. Also find the value of the maximum power.
Description : State condition for resonance in R-L-C series circuit.
Last Answer : The condition for resonance in R-L-C series circuit. i) Inductive Reactance should be equal to capacitive reactance. That is XL = XC ii) The power factor of the circuit is Cos ɸ = 1 iii)The voltage and ... and given by I =V/R. v)Impedance of the circuit is minimum and given by Z =R.
Description : State any Four lE Rules regarding electric safety.
Last Answer : lE Rules regarding electric safety: 1. IE Rule 3 : Authorization 2. IE Rule 29 : Construction and maintenance of electrical supply line and apparatus 3. IE Rule 30: Service line and apparatus on ... 26. IE Rule 60: Test for resistance of insulation 27. IE Rule 61: Connection with earth
Description : State Ohm’s law for electric circuit.
Last Answer : Ohms law -States that the current flows in a circuit is directly proportional to the applied voltage (V) and inversely the proportional resistance provided with the temperature main constant
Description : State advantages of electric heating over other types of heating methods.
Last Answer : Advantages of Electric heating over the other types of heating methods: 1. It can be put into service immediately. 2. No standby losses. 3. High efficiency. 4. More economical ... low attention and supervision. 14. Protection against overheating can be provided by suitable switch gear.
Description : State which electric motors are generally used in electro agro systems with reason.
Last Answer : 1) 3 phase induction motor is used in electro agro system for water pumping from wells as 3 phase ac supply is easily available, cost of induction motor is less, maintenance free being rugged ... as 1 phase ac supply is easily available for domestic purpose, repair is simple and easily available.
Description : State types of enclosures of electric drives.
Last Answer : Types of enclosures of Electric Drives: 1) Screen protected 2) Open type 3) Protected type 4) Totally enclosed 5) Drip-proof type 6) Pipe ventilated type 7) Flame proof type 8) Explosion proof 9) Splash proof.
Description : State elements of diesel electric power plant with their functions.
Last Answer : Elements of Diesel Power Plant with their function): 1) Diesel Engine: - This is the main component of the P.P. which develops mechanical power. 2) Engine air intake system: - Air ... fuel as per requirement. 10) Alternator: - Its function is to convert mechanical power into electrical power.
Description : State any four advantages and four disadvantages of diesel electric power plant.
Last Answer : Advantages of Diesel electric power plant:- 1) The design and layout of Diesel electric power plant is simple. 2) It requires less space. 3) Time required for complete erection of diesel power plant is less ... . 9) The useful life is very short. 10) Availability of fuel in future may be limited.
Description : State various effects of electric current and explain any one.
Last Answer : Effects of Electric Current: 1. Magnetic Effect: When a current is passed through a conductor, magnetic field is produced round the conductor. Due to this field when current carrying ... The rise in temperature is converted into elongation of hot wire element causes displacement of pointer.
Description : Compressor wizards, share your wisdom?
Last Answer : There is this chap that bought a small compressor for electronics dusting purposes and compared it to a normal blower style duster. The compressor was a complete failure.
Description : How would you handle UPS packages with this setup?
Last Answer : Pick them up from the depot…
Description : Q-12 which Testing is used in high thickness job in LNT?
Last Answer : Ultrasonic Testing.
Description : Q-11 What is the purpose of dust free zone in LNT?
Last Answer : Special dust-free enclosures with temperature and humidity control enable the Company to achieve manufacturing excellence in Class 1 nuclear island components. L&T manufactures reactor vessels, steam ... and Heat Exchangers are manufactured within dust-free enclosures at L&T's workshops.
Description : Q-10 In TANDEM SAW process, why AC and DC both currents are used?
Last Answer : AC will melt the base metal and make weld pool in the base metal and by DC it will fill the weld metal in the weld pool.
Description : Q-9 how many electrodes are used in the TANDEM SAW? What is the polarity of the both electrode?
Last Answer : In TANDEM SAW process there are more than one electrode is used. But for first electrode alternative current and for second electrode direct current shall be used.
Description : Q-8 which types of SAW process are used in Larsen and Toubro?
Last Answer : Tandem SAW Narrow groove application As the section thickness of vessel for nuclear and petroleum industry increase, the desire for reduced weld time and material consumption has driven the joint on ... process is carried out. LNT practice that for many of high thickness nuclear pressure vessel.
Description : Q-7 during welding process, why sinusoidal wave form is converted in to the square wave form?
Last Answer : In sinusoidal wave, we get maximum energy at one point only. So for the more amount of maximum energy we can get by converting the sinusoidal wave form in to the square wave form, and more penetration and deposition rate is achieved due to maximum energy.
Description : Q-6 which innovative welding technique is used by L & T in T joint welding?
Last Answer : In T joint welding backing is required in other side while welding on one side. Flux goes on another side from the root opening and that has to be removed before welding other side. During the ... of the job is also not required by other sources since one side of welding serve the purpose.
Description : Q-5 what is the phenomena behind the overhead welding?
Last Answer : In overhead welding during welding flux has more fluidity and comes on the surface when the metal is deposited in the root gape. There are different freezing point metal and the flux. so metal have low ... deposit in the root gape and flux have a high freezing point so its deposit on the metal .
Description : Q -4 what is the purpose of sodium, silicon and potassium in core element?
Last Answer : • Silicon - deoxidize & form slag • Sodium - stabilize arc & form slag • Potassium - stabilizes the arc & form slag
Description : Q-3 Write the energy distribution for different polarity?
Last Answer : DCEP – 67% at electrode and 33% at job. • DCEN – 33 % at electrode and 67% at job. • AC – 50 % at electrode and 50% job.
Description : Q-2 what are the functions of electrode covering in SMAW process?
Last Answer : To facilitate arc ignition and give arc stability. To generate gas for shielding the arc & molten metal from air contamination. To de-oxidise the weld metal and flux impurities into the slag. To ... to support the molten weld metal). To control hydrogen contents in the weld. (basic type)
Description : Q-1 what is the function of copper coating in SAW filler wire?
Last Answer : to assure a good electric contact between wire and contact tip • to assure a smooth feed of the wire through the guide tube, feed rolls and contact tip (decrease contact tube wear) • to provide protection against corrosion
Description : at the terminal of a three-phase 6.6Kv alternator a load R=200 ohm is connected between two-phase and the third phase is opened. Z1=z2=5 ohm Zo=2 find out the fault current .
Last Answer : 32A
Description : The output of two inputs OR gate is zero only when: (a) Both are one (b) Both are zero (c) Either input is 1 (d) None
Last Answer : (b) Both are zero
Description : Photo diode operates in the _______ condition (a) Forward bias (b) null (c) both a & d (d) reverse bias
Last Answer : (d) reverse bias
Description : In the N-type semiconductor the charge carries are a) Holes b) Neutrons c) Protons d) Electrons
Last Answer : d) Electrons
Description : In a P-type semiconductor the charge carriers are a) Electrons b) Holes c) Protons d) Neutrons
Last Answer : b) Holes
Description : A combination of N-type and P-type material is called a) Diode b) Transistor c) Resistor d) Capacitor
Last Answer : a) Diode