AIPMT 2012 Prelims | Dual Nature of Radiation and Matter Question 44 | Physics

A 200 W sodium street lamp emits yellow light of wavelength 0.6 $$\mu $$m. Assuming it to be 25% efficient in converting electrical energy to light, the number of photons of yellow light it emits per second is

1.5 $$ \times $$ 10²⁰

6 $$ \times $$ 10¹⁸

62 $$ \times $$ 10²⁰

3 $$ \times $$ 10¹⁹

AIPMT 2011 Mains

MCQ (Single Correct Answer)

-1

The threshold frequency for a photosensitive metal is 3.3 $$ \times $$ 10¹⁴ Hz. If light of frequency 8.2 $$ \times $$ 10¹⁴ Hz is incident on this metal, the cut- off voltage for the photoelectron emission is nearly

1 V

2 V

3 V

5 V

AIPMT 2011 Prelims

MCQ (Single Correct Answer)

-1

Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively illuminate a metallic surface whose work function is 0.5 eV successively. Ratio of maximum speeds of emitted electrons will be

1 : 4

1 : 2

1 : 1

1 : 5

AIPMT 2011 Prelims

MCQ (Single Correct Answer)

-1

In photoelectric emission process from a metal of work function 1.8 eV, the kinetic energy of most energetic electrons is 0.5 eV. The corresponding stopping potential is

1.8 V

1.3 V

0.5 V

2.3 V

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