1
WB JEE 2022
MCQ (Single Correct Answer)
+1
-0.25
Change Language

Given : The percentage error in the measurements of A, B, C and D are respectively, 4%, 2%, 3% and 1%. The relative error in $$Z = {{{A^4}{B^{{1 \over 3}}}} \over {C{D^{{3 \over 2}}}}}$$ is

A
$${{127} \over 2}\% $$
B
$${{127} \over 5}\% $$
C
$${{127} \over 6}\% $$
D
$${{127} \over 7}\% $$
2
WB JEE 2022
MCQ (Single Correct Answer)
+1
-0.25
Change Language

The Entropy (S) of a black hole can be written as $$S = \beta {k_B}A$$, where kB is the Boltzmann constant and A is the area of the black hole. The $$\beta$$ has dimension of

A
L2
B
ML2L$$-$$1
C
L$$-$$2
D
dimensionless
3
WB JEE 2021
MCQ (Single Correct Answer)
+1
-0.25
Change Language
From dimensional analysis, the Rydberg constant can be expressed in terms of electric charge (e), mass (m) and Planck constant (h) as [consider $${1 \over {4\pi {\varepsilon _0}}} \equiv 1$$ unit]
A
$${{{h^2}} \over {m{e^2}}}$$
B
$${{m{e^4}} \over {{h^2}}}$$
C
$${{{m^2}{e^4}} \over {{h^2}}}$$
D
$${{m{e^2}} \over {{h^2}}}$$
4
WB JEE 2020
MCQ (Single Correct Answer)
+1
-0.25
Change Language
The frequency v of the radiation emitted by an atom when an electron jumps from one orbit to another is given by v = k$$\delta $$E, where k is a constant and $$\delta $$E is the change in energy level due to the transition. Then, dimension of k is
A
$${\left[ {M{L^2}{T^{ - 2}}} \right]}$$
B
the same dimension of angular momentum
C
$${\left[ {M{L^2}{T^{ - 1}}} \right]}$$
D
$$\left[ {{M^{ - 1}}{L^{ - 2}}T} \right]$$
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