JEE Main 2020 (Online) 8th January Morning Slot | Atoms and Nuclei Question 121 | Physics

JEE Main 2020 (Online) 8th January Morning Slot

MCQ (Single Correct Answer)

-1

When photon of energy 4.0 eV strikes the surface of a metal A, the ejected photoelectrons have maximum kinetic energy T_A eV end de-Broglie wavelength $$\lambda _A$$. The maximum kinetic energy of photoelectrons liberated from another metal B by photon of energy 4.50 eV is T_B = (T_A – 1.5) eV. If the de-Broglie wavelength of these photoelectrons $$\lambda _B$$ = 2$$\lambda _A$$, then the work function of metal B is :

1.5eV

4eV

2eV

3eV

JEE Main 2020 (Online) 8th January Morning Slot

MCQ (Single Correct Answer)

-1

The graph which depicts the results of Rutherford gold foil experiment with $$\alpha $$-particales is :
$$\theta $$ : Scattering angle
Y : Number of scattered $$\alpha $$-particles detected (Plots are schematic and not to scale)

JEE Main 2020 (Online) 8th January Morning Slot Physics - Atoms and Nuclei Question 122 English Option 1

JEE Main 2020 (Online) 8th January Morning Slot Physics - Atoms and Nuclei Question 122 English Option 2

JEE Main 2020 (Online) 8th January Morning Slot Physics - Atoms and Nuclei Question 122 English Option 3

JEE Main 2020 (Online) 8th January Morning Slot Physics - Atoms and Nuclei Question 122 English Option 4

JEE Main 2020 (Online) 7th January Morning Slot

MCQ (Single Correct Answer)

-1

The time period of revolution of electron in its ground state orbit in a hydrogen atom is 1.6 $$ \times $$ 10^-16 s. The frequency of revolution of the electron in its first excited state (in s^-1) is :

5.6 $$ \times $$ 10¹²

1.6 $$ \times $$ 10¹⁴

7.8 $$ \times $$ 10¹⁴

6.2 $$ \times $$ 10¹⁵

JEE Main 2019 (Online) 12th April Evening Slot

MCQ (Single Correct Answer)

-1

The electron in a hydrogen atom first jumps from the third excited state to the second excited state and subsequently to the first excited state. The ratio of the respective wavelengths, $${{{\lambda _1}} \over {{\lambda _2}}}$$, of the photons emitted in this process is :

$${{22} \over 5}$$

$${7 \over 5}$$

$${9 \over 7}$$

$${{20} \over 7}$$

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