Description : A freshely prepared radioactive source of half 2 hours emits radiations of intensity which is 64 times the permissible safe level. The minimum time af
Last Answer : A freshely prepared radioactive source of half 2 hours emits radiations of intensity which is 64 times the ... 12 hours C. 24 hours D. 48 hours
Description : If by mistake radioactive substance gets into human body, then from the point of view of radiation damage, the most harmful will be one that emits.
Last Answer : If by mistake radioactive substance gets into human body, then from the point of view of radiation damage, ... neutrons C. `beta`-rays D. `alpha`-rays
Description : A radioactive element gets spilled over the floor of a room. Its half life period is 30 days. If its initial activity is ten times the permissible val
Last Answer : A radioactive element gets spilled over the floor of a room. Its half life period is 30 days. If its initial ... B. 1000 days C. 300 days D. 10 days
Description : A radioactive atom `X` emits a `beta-`particle to produce an atom `Y` which then emits an Particle to give an atom `Z` (1) the atomic number of `X` is
Last Answer : A radioactive atom `X` emits a `beta-`particle to produce an atom `Y` which then emits an Particle to give ... C. 2 and 3 are correct D. 3 is correct
Description : A radioactive element is preset in VIII group of the periodic table. If it emits one `alpha`particle, the new position of the nuclide will be
Last Answer : A radioactive element is preset in VIII group of the periodic table. If it emits one `alpha`particle, the new ... . VI B B. VIII C. VIIB D. I B
Description : A radioactive substance emits? (1) alpha particle (2) beta particle (3) gamma particle (4) all of the three
Last Answer : (4) all of the three Explanation: Radioactive substances are continually producing three kinds of dangerous radiation: alpha particles, beta particles and gamma rays. These types of radiation are invisible to the naked eye, and so you won't see a green glow.
Description : The atomic number of a radioactive element is not changed, when it emits __________ rays. (A) α (B) β (C) γ (D) α & β
Last Answer : (C) γ
Description : Which of the following emits dangerous radioactive wastes forcing the government to eliminate its use? (a) Nuclear energy (b) Water energy (c) Geothermal energy (d) Solar energy
Last Answer : (a) Nuclear energy
Description : Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters? (A) I-131 (B) Sr-90 (C) Au-198 (D) Ra-226
Last Answer : (D) Ra-226
Description : Most of what we call background radiation comes from two sources. One is the naturally radioactive elements around us. What is the other source?
Last Answer : ANSWER: COSMIC RADIATION
Description : How does a microwave oven heat up food even though it emits no thermal radiation? -Physics
Last Answer : A microwave oven does emit thermal radiation to heat up food. Microwave radiation is thermal radiation. For some reason, most sources have a mistaken notion that thermal radiation = infrared radiation ... a broad spectrum of frequencies with a certain shape that depends on the emitter's temperature.
Description : A hydrogen like gas emits radiation of wavelengths `460 Å, 828 Å` and `1035Å`, only. Assume thar the atoms have only two excited states and the differ
Last Answer : A hydrogen like gas emits radiation of wavelengths `460 Å, 828 Å` and `1035Å`, only. Assume ... of the ground state and the first excited state.
Description : When a warm object is heated up why does the thermal radiation emits change?
Last Answer : Feel Free to Answer
Description : When a warm object is heated up why does the thermal radiation it emits changes?
Description : What is a neutron star which a Emits radiation that reaches the earth as radio waves and flashes of visible light?
Last Answer : pulsar
Description : A black body when hot, emits heat radiation of __________ wavelengths. (A) Small (B) Large (C) All (D) One fixed
Last Answer : (C) All
Description : Which one of the following statements is correct? (A) During the day, earth reflects solar radiation (B) During the day, earth reflects both solar radiations the emission from its surface (C) During the night, earth emits radiation from its surface (D) All of these
Last Answer : Answer: Option D
Description : When a solid material is heated, it always: w) emits a discrete radiation spectrum x) glows red y) emits a continuous radiation spectrum z) emits only visible radiation
Last Answer : ANSWER: Y -- EMITS A CONTINUOUS RADIATION SPECTRUM
Description : Identify the meiotic sage in which the homologous chromosomes separate while the sister chromatids remain associated at their centrometres. Or In whic
Last Answer : Identify the meiotic sage in which the homologous chromosomes separate while the sister chromatids remain ... II C. Metaphase I D. Metaphase II
Description : Gross National Product at market prices of an economy is ₹ 65 , 000 crores . The capital stock of the economy is valued at ₹ 1, 20 , 000 crores , whic
Last Answer : Gross National Product at market prices of an economy is ₹ 65 , 000 crores . The capital ... 000 crores . Estimate National Income of the economy.
Description : Whic Internet Service Provider has the fastest Las Vegas service?
Last Answer : Get reliable, fast, and safe TV and internet service from AT&T. AT&T offers bundles with DirecTV and packages included Wi-Fi Equipment and bundled HBO. Save more and get more when you bundle TV with Internet ht tps://cutt.ly/oh0YpBO
Description : Whic of the following pairs of materials serves as electrodes in chargeable batteries commonly used in devices such as torch lights, electric shavers, etc.? (1) Iron and cadmium (2) Nickel and cadmium (3) Lead peroxide and lead (4) Zinc and carbon
Last Answer : (2) Nickel and cadmium Explanation: A rechargeable battery, storage battery, or accumulator is a type of electrical battery. It comprises one or more electrochemical cells, and is a ... sizes, ranging from button cells to megawatt systems connected to stabilize an electrical distribution network.
Description : A linear programm A linear programming model CANNOT be used when whic ing model CANNOT be used when which of the followin h of the following are true? g are true? a)An optimal ... set of linear constraints may be defined d)Cross product relationships exist between two or more decision variables
Last Answer : d)Cross product relationships exist between two or more decision variables
Description : An igneous rock which is commonly black, has a glassy texture, and has a conchoidal (pron: kong-koid-al) fracture is whic of the following? w) pelite (pron: pel-ite) x) calcite y) obsidian z) none of the above
Last Answer : ANSWER: Y -- OBSIDIAN
Description : The activity of a radioactive element reduces to `(1//16)th` of its original value in 30 years. Find its half life?
Last Answer : The activity of a radioactive element reduces to `(1//16)th` of its original value in 30 years. Find its half ... B. 75 trs C. 7.5 day D. 75 month
Description : Threshold limit value (TLV) i.e., the maximum permissible safe limit of phosgene gas which Hitler used to use to kill his enemies in 'gas chamber' is about __________ ppm. (A) < 1 (B) 10-100 (C) 100-200 (D) 100-1000
Last Answer : (A) < 1
Description : Two radioactive elements X and Y have half lives 6 min and 15 min respectively. An experiment starts with 8 times as many atoms of X as Y. how long it
Last Answer : Two radioactive elements X and Y have half lives 6 min and 15 min respectively. An experiment starts with 8 times ... B. 12 min C. 48 min D. 30 min
Description : Faucet A and B can fill a tank in 15 and 9 hrs respectively. Faucet C can empty it in 45 h. The tank is half full. All the three faucets are in operation simultaneously. After how much time the tank will be full ? A) 1(7/15)hrs B) 2(1/11)hrs C) 3(3/14)hrs D) 3(3/11)hrs
Last Answer : C In 1 hr = 1/15+1/9 – 1/45 =>3+5-1/45 = 7/45 ½ tank filled by 3 Faucets = 45/7*1/2 => 45/14 =>3(3/14)
Description : A pump can fill a cistern in 12 hrs. After half the cistern is filled, 3 more similar pumps are opened. What is the total time taken to fill the cistern completely? A) 8 hrs B) 4 hrs C) 2hrs D) 7.5 hrs
Last Answer : D Time taken by 1 pump to fill tha half tank = 6 hrs Part filled by the 4 pumps in 1 hr = 4 * 1/12 =1/12 =>1/3 Remaining part = (1 – 1/2)= 1/2 Therefore 1/3 :1/2 :: 1:x X=1.5 hrs So total time takem = 6hrs + 1.5 hrs = 7.5 hrs.
Description : As per international norms, the maximum permissible value of noise level in the industrial environment is __________ decibels as measured at a distance of 1.5 metres from the source of noise. (A) 110 (B) 85 (C) 60 (D) 45
Last Answer : (B) 85
Description : The rate of emission of radiation, when a radioactive sample is placed in water,_________.
Last Answer : The rate of emission of radiation, when a radioactive sample is placed in water,_________. A. ... C. remains the same D. Cannot be determined
Description : The radiation from naturally occuring radioactive substance as seen after deflection by a magnetic field in one direction are :
Last Answer : The radiation from naturally occuring radioactive substance as seen after deflection by a magnetic field in one ... D. either `alpha` or `beta`-rays
Description : Why Deinococcusradiodurans is able to survive massive exposure to radiation? A- .Because it produces a thick shell which acts as a shield from the radiation B- Because it has unique DNA repair ... its cellwall contains radioactive elements D- Because it has many copies of genes encoding DNA repair
Last Answer : Because it has many copies of genes encoding DNA repair
Description : Which physical phenomenon or principle is most often applied in the search for petroleum reservoirs? w) magnetic field distortions x) electromagnetic radiation y) natural radioactive decay of minerals z) acoustic wave transmission and reflection
Last Answer : ANSWER: Z -- ACOUSTIC WAVE TRANSMISSION AND REFLECTION
Description : Can the decay half-life of a radioactive material be changed? -Physics
Last Answer : Yes, the decay half-life of a radioactive material can be changed. Radioactive decay happens when an unstable atomic nucleus spontaneously changes to a lower-energy state and spits out a bit of ... radiometric dating are so accurate because decay half-lives in nature are so close to constant.
Description : What is the half-life of a radioactive element ?
Last Answer : Half-life is the amount of time during which half of the nucleus of an element is irradiated.
Description : Initial amount of the radioactive element with half life 10 days is 16 g. What amount in gm of this element will remain after 40 days?
Last Answer : Initial amount of the radioactive element with half life 10 days is 16 g. What amount in gm of this element will remain after 40 days?
Description : If `3//4` quantity of a radioactive substance disintegrates in 2 hours, its half`-` life period will be a)`15 mi n` b) `30 mi n` c)`60 mi n` d)`90 mi
Last Answer : If `3//4` quantity of a radioactive substance disintegrates in 2 hours, its half`-` life period will be ... B. 45 minutes C. 30 minutes D. 15 minutes
Description : Radioactive decay follows first-order kinetic. The mean life and half-life of nuclear decay process are `tau = 1// lambda` and `t_(1//2) = 0.693//lamb
Last Answer : Radioactive decay follows first-order kinetic. The mean life and half-life of nuclear decay process are `tau = 1// ... `tau = (t_(1//2))/(0.693)`
Last Answer : Radioactive decay follows first-order kinetic. The mean life and half-life of nuclear decay process ... on the amount of element not yet decayed
Last Answer : Radioactive decay follows first-order kinetic. The mean life and half-life of nuclear decay process are `tau = 1 ... B. 53 yrs C. 530 yrs D. 5300 yrs
Last Answer : Radioactive decay follows first-order kinetic. The mean life and half-life of nuclear decay ... exponentially C. parabolically D. all of these
Last Answer : Radioactive decay follows first-order kinetic. The mean life and half-life of nuclear decay ... lambda` depend on the nature of radioactive element
Last Answer : If `3//4` quantity of a radioactive substance disintegrates in 2 hours, its half`-` life period will be a)`15 mi n ... mi n` c)`60 mi n` d)`90 mi n`
Description : Assertion (A) : Half life of a radioactive isotope is the time required to decrease its mass number by half Reason (R ) : Half life of radioactive iso
Last Answer : Assertion (A) : Half life of a radioactive isotope is the time required to decrease its mass number by half ... . If both (A) and (R ) are incorrect.
Description : At radioactive equilibrium, the ratio between two atoms of radioactive elements `A` and `B` is `3.1 xx 10^(9) : 1`. If the half-life period of `A` is
Last Answer : At radioactive equilibrium, the ratio between two atoms of radioactive elements `A` and `B` is `3.1 xx 10^(9) ... B. 3 yrs C. 3.3 yrs D. None of these
Description : The half life of radioactive isotope is 3 hour. If the initial mass of isotope were 256 g, the mass of it remaining undecayed after 18 hr is a)12 g b)
Last Answer : The half life of radioactive isotope is 3 hour. If the initial mass of isotope were 256 g, the mass of it remaining ... 4 g B. 8 g C. 12 g D. 16 g
Last Answer : At radioactive equilibrium, the ratio between two atoms of radioactive elements `A` and `B` is `3.1 xx 10^(9) : ... . 4.65 yrs C. 5.46 yrs D. 5.64 yrs
Description : A radioactive sample has a half life 1500 years. A sealed tube conataining 1g of the sample will contain after 3000 years,
Last Answer : A radioactive sample has a half life 1500 years. A sealed tube conataining 1g of the sample will contain ... g of the sample D. 0.01g of the sample
Description : A radioactive isotope having a half life of 3 days was received after 12 days. It was found that there were 3 gm of the isotopes in the container. The
Last Answer : A radioactive isotope having a half life of 3 days was received after 12 days. It was found that there were 3 gm of ... 48 g B. 36 g C. 24 g D. 12 g