Description : Which one of the following phenomena can be studied with -rays a) Photoelectric effect b) Compton effect c) Pair production d) All of the above
Last Answer : a) Photoelectric effect
Description : In annihilation of matter the photons produced fly off at the speed of a) Light b) Sound c) Twice the speed of light d) None
Last Answer : a) Light
Description : In the annihilation of matter the number of photons produced is a) One b) Two c) Three d) None
Last Answer : b) Two
Description : Pair production can be studied with a) Ultraviolet rays b) X-rays c) Microwaves d) -rays
Last Answer : d) -rays
Description : The concept that particles can behave like waves was given by a) Compton b) De-Broglie c) G.P. Thomson d) Germer
Last Answer : b) De-Broglie
Description : The reverse effect of X-ray emission is (1) Raman effect (2) Compton effect (3) Zeeman effect (4) Photoelectric
Last Answer : (4) Photoelectric Explanation: When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency ... and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
Description : The reverse effect of X–ray emission is (1) Raman effect (2) Compton effect (3) Zeeman effect (4) Photoelectric
Last Answer : Photoelectric
Description : A device based on photo electric effect is called a) Photo sensitive b) Photo diode c) Photo synthesis d) Photo cell
Last Answer : d) Photo cell
Description : X-rays can penetrate several ____ into a solid matter. a) millimeters b) meters c) centimeters d) kilometers
Last Answer : c) centimeters
Description : The practical application of electrostatic is: (a) Photocopier (b) X-rays machines (c) Laser (d) All of above 42. The electric field lines emerge from the charges in: (a) Three dimensions (b) Two dimensions (c) One dimension (d) All of above
Last Answer : (a) Photocopier
Description : __________ of the following phenomenon cannot be explained on the particle nature of light. A. Photo Electric Effect B. Compton’s Effect C. Pair Production D. Interference
Last Answer : A. Photo Electric Effect
Description : For the production of X-rays, the electrons which strike with the target are a) slow moving b) fast moving c) vibrational electrons d) free electrons
Last Answer : b) fast moving
Description : Which one of the following quantities is conserved in pair production? a) Energy b) Charge c) Linear momentum d) All
Last Answer : d) All
Description : The phenomena of pair production occurs only when the energy of incident photon is least equal a) 10.2 MeV b) 1.02 MeV c) 1.02 eV d) 0.102 MeV
Last Answer : b) 1.02 MeV
Description : Process of conversion low voltage to high voltage is called _______ (a) Rectification (b)forward bias (c) reverse bias (d) amplification
Last Answer : (d) amplification
Description : The photo copying process is called: (a) Xerography (b) Inkjet printer (c) Both (a) and (b) (d) None of these
Last Answer : (a) Xerography
Description : Depletion region of a junction is formed _________ (a) during the manufacturing process (b) under forward bias (c) under reverse bias (d) when temperature varies
Last Answer : (a) during the manufacturing process
Description : The X-rays emitted in inner shell transitions are called _____ as their energy depends upon the type of target material. a) gamma rays b) special X-rays c) Characteristic X-rays d) continuous X-rays
Last Answer : c) Characteristic X-rays
Description : The photoelectric effect is a demonstration of: w) the wave nature of light x) the particle nature of light y) Compton scattering z) the continuous spectrum of radiation
Last Answer : ANSWER: X -- THE PARTICLE NATURE OF LIGHT
Description : In the Compton effect, a photon of wavelength l (read: lambdw) collides with a stationary electron. The wavelength of the emitted photon is: w) longer than l x) shorter than l y) the same as l z) no photon is emitted
Last Answer : ANSWER: W -- LONGER THAN l
Description : X-rays that are emitted in all directions and with a continuous range of frequencies are known as a) characteristic X-rays b) continuous X-rays c) scattered X-rays d) stimulated X-rays.
Last Answer : b) continuous X-rays
Description : X-rays were discovered by: a) Roentgen b) Becquerel c) Marie Curie d) Van Lave
Last Answer : a) Roentgen
Description : In human flesh, the three light elements which predominate, and allow greater amount of incident X-rays to pass through them are a) oxygen, nitrogen , hydrogen b) oxygen, hydrogen, helium c) oxygen, hydrogen, carbon d) carbon, nitrogen, oxygen
Last Answer : c) oxygen, hydrogen, carbon
Description : By the transition of inner shell electrons in heavy atoms, high energy photons are emitted which are a) gamma rays b) X-rays c) radio waves d) photon rays
Last Answer : b) X-rays
Description : Which one of the following radiations has the most energetic photon? a) T.V. waves b) Micro waves c) X-rays d) - rays
Last Answer : d) - rays
Description : Which one of the following waves requires a material medium for their propagation? a) Light waves b) X– rays c) -rays d) Sound waves
Last Answer : d) Sound waves
Description : The potential difference set up across the depletion region is called (a) Absolute potential (b) neutral potential (c) reverse potential (d) potential barrier
Last Answer : (d) potential barrier
Description : The minimum frequency required to eject electrons from a metallic surface is called a) Critical frequency b) Peak value of frequency c) Threshold frequency d)Photo frequency
Last Answer : c) Threshold frequency
Description : The minimum energy required to eject an electron from a metal surface is called a) Intensity b) Threshold frequency c) Work function d) Photo energy
Last Answer : c) Work function
Description : Colors in thin films are because of A. Dispersion C. Interference B. Compton effect D. Diffraction
Last Answer : C. Interference
Description : Which of the following does not support the wave nature of light A. Interference C. Polarisation B. Compton effect D. Diffraction
Last Answer : B. Compton effec
Description : How do you test reverse power trip, high current trip, preferential trip?
Last Answer : Reverse power trip - refer answer for question 11. Also ask E/O. High current (over load trip) - Set your overload relay high current trip setting to say 75% of the rated current. Run the ... loads to overload the generator. Preferential trip will trip all the non-critical loads. Also ask E/O.
Description : Why is this reverse power used instead of reverse current in alternators?
Last Answer : It is extremely difficult to detect reverse current with an alternating current system, reverse power can be detected and protection can be provided by reverse power relay.
Description : How do you test reverse power trip?
Last Answer : When two generators are running in parallel and one generator can carry the load, reverse power trip can be tested by load shifting using governor control. When the load has shifted sufficiently and the off ... (using the test push button on the relay) to see if it initiates a trip signal.
Description : How is the protection against reverse power given?
Last Answer : Reverse power protection is used for anti-motoring. This function is used for protection of prime mover not generator. It can cut-off the fuel supply and stop the prime mover.
Description : What is the harm if reverse power flows?
Last Answer : Assume that the generator normally produces an amount of power equal to P, and that when operating as a motor, it will absorb a similar amount, P. Therefore, the net effect on the grid will ... change on the grid. There could be prime mover damage in some instances (especially steam turbines).
Description : When does Reverse power flow?
Last Answer : Situation of a generator is feeding a system through switchgear having several generators connected in parallel with this generator. The flow of current, when the system is running normally, is from the ... minor to extreme in the event of a complete mechanical failure of the generator which fails.
Description : In the reverse biased p-n junction, the current is of the order of (a) Ampere (b) Milliampere (c) Microampere (d) Nano-ampere
Last Answer : (d) Nano-ampere
Description : On increasing the reverse bias to a large value in a p-n junction diode current (a) Increases slowly (b) Remains fixed (c) Suddenly increases (d) Decreases slowly
Last Answer : (c) Suddenly increases
Description : The reverse current through semiconductor diode is due to (a) Minority carrier (b) majority carrier (c) electrons (d) holes
Last Answer : (a) Minority carrier
Description : For normal operation of a transistor, the collector base junction is kept (a) Unbiased (b) forward biased (c) reverse biased (d) none
Last Answer : (c) reverse biased
Description : ___________ remain undeflected in a magnetic field a) β particles b) α particles c) γ rays d) Proton beams
Last Answer : c) γ rays
Description : What is a photo cell?*
Last Answer : A cell whose resistance varies with intensity of light.
Description : Asingle fiber can handle asmanyvoice channel as a. a pair of copper conductors b. a1500-pair cable c. a 500-pair cable d. a 1000-pair cable
Last Answer : b. a1500-pair cable
Description : If energy of incident photon is greater than the rest mass energy of electron positron pair, the surplus energy is shared by the pair as, a) Potential energy b) Thermal energy c) Electronic energy d) Kinetic energy
Last Answer : d) Kinetic energy
Description : The continuous X-ray spectrum is obtained due to the effect called a) Braking radiation b) Bremsstrahlung c) both a & b d) none of a & b
Last Answer : b) Bremsstrahlung
Description : Are we on our way to self annihilation?
Last Answer : answer:I love your topic tag. :D Mankind has been through a lot. I don’t know if war and violence will destroy us since it’s happened for centuries and we still be kickin’, but the rate by which we destroy the vital resources we require for survival is another story altogether.
Description : What is an annihilation set ?
Last Answer : If two sets do not have any common elements, then those two sets are called mutually exclusive sets.
Description : de Broglie’s relation for matter waves was experimentally verified by: a) Davisson b) Germer c) G.P. Thomson d) All the these
Last Answer : c) G.P. Thomson
Description : The concept of matter waves was introduced by a) Davisson and Germer b) de Broglie c) Einstein d) Schrodinger
Last Answer : b) de Broglie