Related InterviewSolutions

• The half-life of a radioactive substance is 10 days. This means thatA. The substance completely disintegrates in 20 daysB. The substace completely disintegrates in 40 daysC. `1//8` part of the mass of the substance will be left intact at the end of 40 daysD. `7//8` part of the mass of the substance disintegrates in 30 days
• The count rate of a Geiger Muller counter for the radiation of a radioactive material of half-life `30` min decreases to `5 s^(-1)` after `2 h`. The initial count rate wasA. 80 `second^(-1)`B. 625 `second^(-1)`C. 20 `second^(-1)`D. 25 `second^(-1)`
• A nucleus X, initially at rest , undergoes alpha dacay according to the equation , ` _(92)^(A) X rarr _(Z)^(228)Y + alpha ` (a) Find the value of `A` and `Z` in the above process. (b) The alpha particle produced in the above process is found to move in a circular track of radius `0.11 m` in a uniform magnetic field of `3` Tesla find the energy (in MeV) released during the process and the binding energy of the parent nucleus X Given that `: m (Y) = 228.03 u, m(_(0)^(1)n) = 1.0029 u. ` `m (_(2)^(4) He) = 4.003 u , m (_(1)^(1) H) = 1.008 u `
• The radioactive nucleus of an element X decays to a stable nucleus of element Y.A graph of the rate of romation of Y against time would look like:A. B. C. D.
• Some amount of a radioactice substance (half-life =10 days ) is spread inside a room and consequently the level of radiation become `50` times the permissible level for normal occupancy of the room. After how many days will the room be safe for occupation?.
• A radioactive nucleus undergoes a series of deacy according to the scheme. `Aoverset(alpha)rarrA_(1)overset(beta^(-))rarrA_(2)overset(alpha)rarrA_(3)overset(gamma)rarrA_(4)` If the mass number and atomic number of `A` are `180` and `172` respectively, what are these numbers for `A_(4)`.
• Suppose a nucleus initally at rest undergoes `alpha` decay according to equation `._(92)^(225)X rarr Y +alpha` At `t=0`, the emitted `alpha`-particles enter a region of space where a uniform magnetic field `vec(B)=B_(0) hat i` and elecrtic field `vec(E)=E_(0) hati` exist. The `alpha`-particles enters in the region with velocity `vec(V)=v_(0)hat j` from `x=0`. At time`t=sqrt3xx10^(6) (m_(0))/(q_(0)E_0)s`, the particle was observed to have speed twice the initial velocity `v_(0)`. Then, find (a) the velocity `v_(0)` of the `alpha`-particles, (b) the initial velocity `v_(0)` of the `alpha`-particle, (c ) the binding energy per nucleon of the `alpha`-particle. `["Given that" m(Y)=221.03 u,m(alpha)=4.003 u,m(n)=1.09u,m(P)=1.008u]`.
• A nuclide `A` undergoes `alpha`-decay and another nuclides `B` undergoes `beta`-decayA. All the `alpha`-particles emitted by A will have almost the same speedB. The `alpha`-particles emitted by A may have widely different speedsC. Al lthe `beta`-particles emitted by B will have almost the same speedD. The `beta`-particles emitted by B will have different speeds
• A radioactive nucleus `X `decay to a nucleus `Y` with a decay with a decay Concept `lambda _(x) = 0.1s^(-1) , gamma ` further decay to a stable nucleus Z with a decay constant `lambda_(y) = 1//30 s^(-1)` initialy, there are only X nuclei and their number is `N_(0) = 10^(20)` . Set up the rate equations for the population of `X , Y and Z` The population of `Y` nucleus as a function of time is given by `N_(y) (1) = N_(0) lambda_(x)l(lambda_(x) - lambda_(y))( (exp(- lambda_(y)t))` Find the time at which `N_(y)` is maximum and determine the populations `X and Z` at that instant.
• A radioactive element `A` with a half-value period of `2` hours decays giving a stable element `Y`. After a time `t` the ratio of `X` and `Y` atoms is `1 : 7` then `t` is :A. 6 hoursB. 8 hoursC. 10 hoursD. 12 hours