Description : Fifty micrograms of an isotope have decayed to 12.5 micrograms after 12 hours. What is the half life of the radioisotope?
Last Answer : ANSWER: SIX HOURS
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
Description : What is the half life of 3 g sample of radioisotope that decay to 0.75 g in 30 days?
Last Answer : 15 days
Description : The half life period of a radioactive element is 100 days. After 400 days, one gm of the element will be reduced to __________ gm. (A) 1/4 (B) 1/8 (C) 1/2 (D) 1/16
Last Answer : (D) 1/16
Description : A radioisotope has a half life of 10 days. If today there is `125 g ` of it left, what was its mass 40 days earlier ? a)600g b)1000g c)1250g d)2000g
Last Answer : A radioisotope has a half life of 10 days. If today there is `125 g ` of it left, what was its mass ... d)2000g A. 600g B. 1000g C. 1250g D. 2000g
Description : If the half-life of a radioisotope is 2 days, after how many days is the quantity reduced to 12.5% of its original amount? w) 4 days x) 6 days y) 8 days z) 10 days
Last Answer : ANSWER: X -- 6 DAYS
Description : The half-life of an isotope of an element is 5 days. The mass of a 10 gram sample of this isotope remaining after 20 days is: w) 0.312 grams x) 0.625 grams y) 1.25 grams z) 2.50 grams
Last Answer : ANSWER: X -- 0.625 GRAMS
Description : The amount of a radioisotope remaining undecayed after a time equal to four times its half life, will be __________ percent. (A) 3.125 (B) 6.25 (C) 12.50 (D) 25
Last Answer : (B) 6.25
Description : Pick out the wrong statement. (A) α-particle emission from a radioactive element makes it electrically negative (B) β-particle emission from a radioactive element makes it electrically ... ) The disintegration constant of a radioactive isotope is independent of pressure, temperature or concentration
Last Answer : (C) A radioactive element having a half life period of 20 years will completely disintegrated in 40 years
Description : A radioactive isotope has a half-life of 10 days. If today there are 125 g of it left, what was its original weight 40 days earlier (a) 600 g (b) 1000 g (c) 1250 g (d) 2000 g
Last Answer : Half life = 10days The formula which is, 1/(2)^n × original weight = Weight left today. To obtain the value of n = divide no of days by half life ie.,n= 40/10= 4 n=4 So, 1/(2)^n × original Weight = 125g 1/(2)^4 × Original weight = 125 Original weight = 16×125 = 2000g
Description : Why is there no formula to compute the half-life of any given radioisotope?
Last Answer : I don’t think the theories contain enough information about what is actually going on with subatomic particles that leads to those results.
Description : The radioisotope , tritium `(""_(1)^(3)H)` has a half-life of 12.3 years. If the initial amount of tritium is 32 mg , how many milligrams of it would
Last Answer : The radioisotope , tritium `(""_(1)^(3)H)` has a half-life of 12.3 years. If the initial amount of tritium is 32 ... A. 1 mg B. 2 mg C. 4 mg D. 8 mg
Description : What is the half life of 12 g sample of radioisotope that decayed to 6 g in 28 years?
Last Answer : 28 years
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 : The time required for half of the __________ of a radioactive isotope to decay is called its half life. (A) Nuclei (B) Electrons
Last Answer : (A) Nuclei
Description : The `t_(1//2)` of a radionuclide is 8 hours. Starting with 40 g of the isotope, the amount in gm remainig after one day will be:
Last Answer : The `t_(1//2)` of a radionuclide is 8 hours. Starting with 40 g of the isotope, the amount in gm remainig after one day will be:
Description : Dust content in raw blast furnace gas is about __________ gm/Nm3 ; hence it is cleaned to the dust level of about < 10 mg /Nm3 before use. (A) 15-30 (B) 1-2 (C) 70-100 (D) 150-200
Last Answer : (A) 15-30
Description : Liquefied Petroleum Gas (LPG) in domestic use cylinders is in the liquid form. The density of LPG in liquid form is about __________ of that of water (i.e. 1 gm/c.c). (A) One fourth (B) One third (C) Half (D) One eighth
Last Answer : (C) Half
Description : The compressive strength of cement should not be less than about 110Kg/cm2 after three days & not less than 170Kg/cm2 after seven days. The fineness of an ordinary cement as determined by turbidimetric method should be about __________ cm2 /gm. (A) 800 (B) 1600 (C) 4000 (D) 8500
Last Answer : (B) 1600
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 : Slow sand filter is used if maximum turbidity of raw water is less than (A) 10 gm/litre (B) 20 gm/litre (C) 30 gm/litre (D) 50 gm/litre
Last Answer : (D) 50 gm/litre
Description : If the interest rate of 10% per period is compounded half yearly, the actual annual return on the principal will be __________ percent. (A) 10 (B) 20 (C) > 20 (D) < 20
Last Answer : (C) > 20
Description : When a radioisotope undergoes beta minus decay, does its atomic number: w) increase x) decrease y) remain the same z) vary depending on the element involved
Last Answer : ANSWER: W -- INCREASE
Description : The `.^(60)C` isotope decays with a half life of 5.3 years. How long would it take for 7/8 of a sample of 500 mg of `.^(60)Co` to disintegrate?
Last Answer : The `.^(60)C` isotope decays with a half life of 5.3 years. How long would it take for 7/8 of a sample ... B. 15.9 years C. 10.6 years D. 5.3 years
Description : The haemoglobin content per 100 mL of blood of a normal healthy human adult is (a) 5 - 11 gm (b) 25 - 30 gm (c) 17 - 20 gm (d) 12 - 16 gm.
Last Answer : (d) 12 - 16 gm.
Description : What is the half-life of carbon 12 isotope ?
Last Answer : Carbon -12 is a normal atom. It is not radioactive. C- 14 is radioactive. Its half -life is 5,630 years
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 : 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
Description : What fraction of an original sample of a radio isotope remains after 3 half-life periods?
Last Answer : One eighth remains.
Description : The radioisotope used to study the thyroid gland is (A) Iodine (B) Cobalt (C) Iron (D) Carbon
Last Answer : (A) Iodine
Description : In normal conditions, the period for sludge digestion, is A. 10 days B. 20 days C. 30 days D. 60 days
Last Answer : ANS: C
Description : Wheat and bajra have critical period of crop-weed competition a).10-20 days b).15-30 days c). 30-45 days d). 20-40 days
Last Answer : c). 30-45 days
Last Answer : Radioisotope is used to diagnose goiter.
Description : The activity of radioisotope changes with:
Last Answer : The activity of radioisotope changes with: A. temperature B. pressure C. chemical enviorment D. none of these
Description : Is a nucleonic sensing method employing usually one or more radioisotope sources and radiation detectors.
Last Answer : Radiation sensing
Description : Rubika can do the 12 times the actual work in 72 days while sathya can do the one-half of the original work in 6 days. In how many days will both working together complete the 6 times of the original work? a) 20 days b) 25 days c) 30 days d) 35 days
Last Answer : C Efficiency of Rubika = 16.666% Efficiency of sathya = 4.166% Total efficiency of rubika and sathya =(16+4) =20% Actual work 100/20=5 So, they can do actual work in 5 days So, 6 times work requires 30 days.
Description : What name is given to the time taken for half the atoms in a sample of a radioactive isotope to decay?
Last Answer : Half-life
Description : The half life of Ig A is (A) 6 days (B) 2–4 days (C) 5–10 days (D) 12–20 days
Last Answer : Answer : A
Description : The half-life of IgG is (A) 2–3 days (B) 5–6 days (C) 8–10 days (D) 20–25 days
Last Answer : Answer : D
Description : The herpes simplex virus (HSV-1), which produces a cold sore (fever blister), has an incubation period of a) 2-12 days. HSV-1 is transmitted primarily by direct contact with infected secretions. b) ... the incubation period. d) 3-6 months. The time period 3-6 months exceeds the incubation period.
Last Answer : a) 2-12 days. HSV-1 is transmitted primarily by direct contact with infected secretions.
Description : A radioactive isotope undergoes decay with respect to time following __________ law. (A) Logarithmic (B) Exponential (C) Linear (D) Inverse square
Last Answer : (B) Exponential
Description : The half life of Ig E protein is (A) 1–6 days (B) 2–8 days (C) 10 days (D) 20 days
Description : The half life of Ig D is (A) 1 day (B) 2–8 days (C) 10–15 days (D) 20–24 days
Last Answer : Answer : B
Description : Repetitive flight plans (RPL's) cannot be used for flights other than those executed frequently on the same days of the following weeks and: a. For at least 20 occasions or every day over a period of ... or every day over a period of at least 10 consecutive days d. For at least 20 occasions
Last Answer : c. For at least 10 occasions or every day over a period of at least 10 consecutive days
Description : A cube of wood supporting 200 gm mass just floats in water. When the mass is removed, the cube rises by 2 cm the side of the cube will be a.5 cm b.10 cm c.12.5 cm d.20 cm e.15 cm
Last Answer : a. 5 cm
Description : Daily excretion of nitrogen by an adult man is about (A) 15–20 mg (B) 1.5–2 gm (C) 5–10 gm (D) 15–20 gm
Last Answer : Answer : C
Description : 75% of a radioactive element decays in 6 hours. Its half life period is __________ hours. (A) 3/4 (B) 1/6 (C) 3 (D) 4
Last Answer : (C) 3
Description : The time taken for a radioactive element to reduce to 50% of its original weight is __________ years, if its half life period is 12 years. (A) 24 (B) 18 (C) 6 (D) 36
Last Answer : (B) 18