Dual Nature, Atoms & Nuclei · JEE Main previous year questions

2002 3 questions

1. Q1362002 · 27 Apr 2002 · Shift 1

   If $13.6\mathrm{eV}$ energy is required to ionize the hydrogen atom, then the energy required to remove an electron from $n=2$ is

   1. A.$10.2\mathrm{eV}$
   2. B.$0\mathrm{eV}$
   3. C.$3.4\mathrm{eV}$
   4. D.$6.8\mathrm{eV}$.
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   Answer: C

2. Q1382002 · 27 Apr 2002 · Shift 1

   Sodium and copper have work functions $2.3\mathrm{eV}$ and $4.5\mathrm{eV}$ respectively. Then the ratio of the wavelengths is nearest to

   1. A.$1:2$
   2. B.$4:1$
   3. C.$2:1$
   4. D.$1:4$
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   Answer: C

3. Q1462002 · 27 Apr 2002 · Shift 1

   If $N_0$ is the original mass of the substance of half-life period $t_{1/2}=5$ years, then the amount of substance left after $15$ years is

   1. A.$N_0/8$
   2. B.$N_0/16$
   3. C.$N_0/2$
   4. D.$N_0/4$
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   Answer: A