NEET 2021 | Dual Nature of Radiation and Matter Question 9 | Physics

NEET 2021

MCQ (Single Correct Answer)

-1

An electromagnetic wave of wavelength '$$\lambda$$' is incident on a photosensitive surface of negligible work function. If 'm' mass is of photoelectron emitted from the surface has de-Broglie wavelength $$\lambda$$_d, then :

$$\lambda = \left( {{{2h} \over {mc}}} \right){\lambda _d}^2$$

$$\lambda = \left( {{{2m} \over {hc}}} \right){\lambda _d}^2$$

$${\lambda _d} = \left( {{{2mc} \over h}} \right){\lambda ^2}$$

$$\lambda = \left( {{{2mc} \over h}} \right){\lambda _d}^2$$

NEET 2020 Phase 1

MCQ (Single Correct Answer)

-1

Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled?

four times

one-fourth

zero

doubled

NEET 2020 Phase 1

MCQ (Single Correct Answer)

-1

Light with an average flux of 20 W/cm² falls on a non-reflecting surface at normal incidence having surface area 20 cm². The energy received by the surface during time span of 1 minute is :

12 $$ \times $$ 10³ J

24 $$ \times $$ 10³ J

48 $$ \times $$ 10³ J

10 $$ \times $$ 10³ J

NEET 2020 Phase 1

MCQ (Single Correct Answer)

-1

An electron is accelerated from rest through a potential difference of V volt. If the de-Broglie wavelength of the electron is 1.227 $$ \times $$ 10^-2 nm, the potential difference is :

10² V

10³ V

10⁴ V

10 V

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