Lifetimes of the molecules in the excited states are often measured by using pulsed radiation source of duration nearly in the nano second range. If the radiation source has the duration of 2 ns and number of photons emitted during the pulse source is 2.5 × 1015, the energy of the source is

Question

Lifetimes of the molecules in the excited states are often measured by using pulsed radiation source of duration nearly in the nano second range. If the radiation source has the duration of 2 ns and number of photons emitted during the pulse source is 2.5 × 1015, the energy of the source is (A) 8.28 × 10-10 J (B) 8 .2 8 × 10-10 J (C) 5 × 10-10 J (D) 82.8 × 10-10 J

Tardigrade Admin · Accepted Answer

Frequency ( mathrmv)=(1/2 × 10-9) =0.5 × 109 mathrm~s-1 Energy of the source =N × h v =2.5 × 1015 × 6.626 × 10-34 × 0.5 × 109 =8.28 × 10-10 mathrm~J

$8.28 \times 1 0^{- 10} J$

$8.28 \times 1 0^{- 10} J$

$5 \times 1 0^{- 10} J$

$82.8 \times 1 0^{- 10} J$

Frequency $(v) = \frac{1}{2 \times 1 0 ^{- 9}}$
$= 0.5 \times 1 0^{9} s^{- 1}$
Energy of the source $= N \times h v$
$= 2.5 \times 1 0^{15} \times 6.626 \times 1 0^{- 34} \times 0.5 \times 1 0^{9}$
$= 8.28 \times 1 0^{- 10} J$

Q. Lifetimes of the molecules in the excited states are often measured by using pulsed radiation source of duration nearly in the nano second range. If the radiation source has the duration of 2ns and number of photons emitted during the pulse source is 2.5×1015, the energy of the source is

8.28×10−10J

8.28×10−10J

5×10−10J

82.8×10−10J

Frequency (v)=2×10−91​ =0.5×109 s−1 Energy of the source =N×hv =2.5×1015×6.626×10−34×0.5×109 =8.28×10−10 J

$8.28 \times 1 0^{- 10} J$

$8.28 \times 1 0^{- 10} J$

$5 \times 1 0^{- 10} J$

$82.8 \times 1 0^{- 10} J$

Frequency $(v) = \frac{1}{2 \times 1 0 ^{- 9}}$
$= 0.5 \times 1 0^{9} s^{- 1}$
Energy of the source $= N \times h v$
$= 2.5 \times 1 0^{15} \times 6.626 \times 1 0^{- 34} \times 0.5 \times 1 0^{9}$
$= 8.28 \times 1 0^{- 10} J$