AIEEE 2003 | Atoms and Nuclei Question 236 | Physics

When a $${U^{238}}$$ nucleus originally at rest, decays by emitting an alpha particle having a speed $$'u',$$ the recoil speed of the residual nucleus is

$${{4\mu } \over {238}}$$

$$ - {{4\mu } \over {234}}$$

$$ {{4\mu } \over {234}}$$

$$ - {{4\mu } \over {238}}$$

AIEEE 2003

MCQ (Single Correct Answer)

-1

Out of Syllabus

A nucleus with $$Z=92$$ emits the following in a sequence: $$$\alpha ,{\beta ^ - },{\beta ^ - },\alpha ,\alpha ,\alpha ,\alpha ,\alpha ,{\beta ^ - },{\beta ^ - },\alpha ,{\beta ^ + },{\beta ^ + },\alpha $$$

Then $$Z$$ of the resulting nucleus is

$$76$$

$$78$$

$$82$$

$$74$$

AIEEE 2003

MCQ (Single Correct Answer)

-1

Out of Syllabus

A radioactive sample at any instant has its disintegration rate $$5000$$ disintegrations per minute. After $$5$$ minutes, the rate is $$1250$$ disintegrations per minute. Then, the decay constant (per minute) is

$$0.4$$ $$ln2$$

$$0.2$$ $$ln2$$

$$0.1$$ $$ln2$$

$$0.8$$ $$ln2$$

AIEEE 2003

MCQ (Single Correct Answer)

-1

The wavelengths involved in the spectrum of deuterium $$\left( {{}_1^2\,D} \right)$$ are slightly different from that of hydrogen spectrum, because

the size of the two nuclei are different

the nuclear forces are different in the two cases

the masses of the two nuclei are different

the attraction between the electron and the nucleus is different in the two cases