Fill in the blanks with appropriate items :
The `alpha` -activity of `1 gm .^(226) Ra. (t_(1//2)=1620 ` year) is _______ dpm.
1 Answers
Talk Doctor Online in Bissoy App
A nucleus with Z =92 emits the following in a sequence: `alpha,beta^(-),beta^(-),alpha,alpha,alpha,alpha,alpha,beta^(-),beta^(-),alpha,beta^(+),beta^(
Correct Answer - B `8 alpha` have been emitted `4 beta^(-)` have been emitted `2 beta^(+)` have emitted `alpha` reduces atomic number by 2 `beta^(-)` increases atomic number by 1 `beta^(+)`...
2 Answers 2 views
A radioactive sample had an initial activily of 56 dpm (disintegration per min). After `69.3 min` it was found to have an activity of 28 dpm. Find the
Correct Answer - B Initial activity = 56 dpm after `69.3` min activity = 28 dpm `:. T_(1//2) =69.3 min " " lambda =(0.693)/(t_(1//2))=(0.693)/(69.3)=10^(-2min)` Activity `=lambda N` `10=10^(-2)xxN " " rArr...
2 Answers 1 views
Fill in the blanks with appropriate items : The number of ` alpha` and `beta ` - particles emitted, when the following nuclear transformation takes pl
Correct Answer - 8,6 `._(92)^(238)X rarr. _(82)^(206)Y + x alpha + y alpha` `._(92)^(238)X rarr ._(82)^(206) Y + x(._(2)He^(4))+y(._(-1)^(0)e)` Comparing mass no. `238 rArr 206 + 4x +0y` `x=8 i.e. 8...
2 Answers 1 views
Fill in the blanks with appropriate items : The half-life period of radioactive element _______ minute if 75% of it disintegrates in 40 min.
Correct Answer - 20 min. `t_(3//4)=2t_(1//2)=40 =2t_(1//2) rArr t_(1//2)=20 min`
2 Answers 1 views
Fill in the blanks with appropriate items : When `._(c)^(a) X` changes to `._(d)^(b) Y` number if ` alpha` and `beta` particle emitted respectively ar
Correct Answer - `alpha=(a-b)/(4) ; beta = d+((a-b))/(2)-c` `._(c)^(a)M rarr ._(d)^(b)N+x(._(2)He^(4))+y(._(-1)e^(0))` `a=b+4x+0y` `(a-b)/(4)=x " " ..........(1)` `c=d+2x-y` `c-d-(a-b)/(2)=-y` `y=d+((a-b))/(2)=c`
2 Answers 1 views
Fill in the blanks with appropriate items : The half life of the nuclide `Rn^(220)` is `54.5 sec`., _______ kg of radon is equivalent to 1 millicurie.
Correct Answer - `1.06 xx 10^(-15)` `A=Nlambda` ` 1xx10^(-3) xx3.7 xx10^(10)` d.p.s `=Nxx(0.693)/(54.5) " " ` 1curie`=3.7 xx 10^(10)` d.p.s. `N=290.98 xx10^(7) rArr (N)/(N_(A))=(29.98 xx10^(7))/(6.023 xx10^(23))=48.31 xx 10^(-16)` moles Mass of...
2 Answers 1 views
`U^(238)` is found to be in secular equilibrium with `Ra^(226)` on its ore. If chemical analysis shows 1 nuclei of `Ra^(226)` per `3.6xx10^(-6)` nucle
According to secular equilibrium. `lamda_(U)N_(U)=lamda_(Ra)N_(Ra)` where, `lamda_(U)=` decay constant of uranium `lamda_(Ra)=` decay constant of Ra `N_(U)`= number of nuclei of U `N_(Ra)` = number of nuclei of Ra We...
2 Answers 1 views
If `A=[alphabetagamma-alpha]` is such that `A^2=I` , then `1+alpha^2+betagamma=0` (b) `1-alpha^2+betagamma=0` (c) `1-alpha^2-betagamma=0` (d) `1+alpha
Correct Answer - A `A^(2) =I` `implies [{:(alpha,beta),(gamma,-alpha):}][{:(alpha,beta),(gamma,-alpha):}]=I` `implies[{:(alpha^(2)+betagamma,alphabeta-betaalpha),(gammaalpha -alphagamma,betagamma +alpha^(2)):}]=I` `implies [{:(alpha^(2) +beta gamma ,0),(0, alpha^(2) +betagamma ):}]=[{:(1,0),(0,1):}]` `alpha^(2) +beta gamma =1 implies 1-alpha^(2) -betagamma =0`
2 Answers 1 views
If a variable takes the discrete values `alpha-4`, `alpha -(7)/(2), alpha-(5)/(2), alpha-2,alpha+(1)/(2), alpha-(1)/(2), alpha+5(alpha gt 0)`, then th
Correct Answer - A Arrange the data as follows : `alpha-(7)/(2), alpha-3, alpha-(5)/(2),alpha-2, alpha-(1)/(2),alpha+(1)/(2),alpha+4,alpha+5` Median `=(1)/(2)` [value of 4th item+value of 5th item] `therefore " Median"=(alpha-2+alpha-(1)/(2))/(2)=(2alpha-(5)/(2))/(2)=alpha-(5)/(4)`
2 Answers 1 views
Prove that `tan alpha+2 tan 2 alpha+2^(2)tan^(2)alpha+..............+2^(n-1)tan2^(n-1)alpha+2^(@)cot2^(@)alpha=cotalpha`
We know `tan theta=cot theta-2 cot 2 theta`. Putting `theta=alpha,2alpha,2^(2)alpha,....................` in (i), we get `tan alpha=(cot alpha-2 cot 2alpha)` `2(tan2alpha)=2(cot 2 alpha-2 cot 2 ^(2)alpha)` `2^(2)(tan2^(2)alpha)=2^(2)(cot2^(2)alpha-2cot2^(3)alpha)` `2^(n-1)(tan2^(n-1)alpha)=2^(n-1)(cot2^(n-1)alpha-2cos2^(n)alpha)` Adding, `tan alpha+2tan...
2 Answers 1 views