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JEE PHYSICS MCQ: UNITS & MEASUREMENTS

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A student makes 10 one-second measurements of the disintegration of a sample of a long-lived radioactive isotope and obtained the following values

3,0,2,1,2, 4,0,1,2,5

. How long should the student want to establish the rate to an uncertainity of 1 per cent? (Given standard deviation of count rate of a radioactive decay

=\sqrt{\text { mean decay rate)}}

View answer and explanation

Correct option: D

5000 sec

The correct answer is D (5000 sec). The time required is calculated by determining the number of counts needed for a 1% uncertainty and then dividing by the average count rate.

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\sqrt{\frac{\text { Modulus of elasticity }}{\text { Density }}}

\mathrm{ms}^{-1} \text {. }

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\frac{1}{\left(\sqrt{\varepsilon_0 \mu_0}\right) t} \text {. }

The method of dimensional analysis can be used to derive which of the following relations? Statement-I: Dimensions of constant of proportionality of constants can be derived from dimensional method
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\left[ {{\mathrm{M}^{ - 1}}{\mathrm{L}^{ - 3}}{\mathrm{A}^2}{T^3}} \right]

is A quantity X is given by

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