Physics

Question 1

1The maximum kinetic energy of photoelectrons depends on

Medium

A. the intensity of the light B. the area of the metal C. the frequency of the light D. the time of exposure

Question 2

2The work function is the same for all metals.

Easy

A. True B. False

Question 3

31 eV = 1.6 × 10⁻¹⁹ J.

Easy

A. True B. False

Question 4

4Find the frequency of light of wavelength 300 nm. (c = 3 × 10⁸ m/s)

Medium

A. 1 × 10¹⁶ Hz B. 1 × 10¹⁵ Hz C. 1 × 10⁻¹⁵ Hz D. 1 × 10¹⁴ Hz

Question 5

5Find the energy of a photon of frequency 1 × 10¹⁵ Hz. (h = 6.6 × 10⁻³⁴ J s)

Medium

A. 6.6 × 10⁻¹⁸ J B. 6.6 × 10⁻⁴⁹ J C. 6.6 × 10⁻¹⁹ J D. 1.52 × 10⁴⁸ J

Question 6

6An electron-volt is the energy

Medium

A. of one photon B. gained by an electron accelerated through a p.d. of 1 V C. of a proton at rest D. in one joule

Question 7

7The photoelectric effect provides evidence that light

Medium

A. is a longitudinal wave B. has particle (photon) properties C. has no energy D. travels faster in glass

Question 8

8Find the frequency of light of wavelength 400 nm. (c = 3 × 10⁸ m/s)

Medium

A. 7.5 × 10¹⁴ Hz B. 7.5 × 10¹³ Hz C. 7.5 × 10¹⁵ Hz D. 1.33 × 10⁻¹⁵ Hz

Question 9

9A line emission spectrum is produced when

Medium

A. electrons are removed completely B. atoms absorb all light C. electrons in atoms fall from higher to lower energy levels D. nuclei split

Question 10

10Light of photon energy 5 eV falls on a metal of work function 3 eV. Find the maximum kinetic energy of the photoelectrons.

Medium

A. 0.6 eV B. 8 eV C. 5 eV D. 2 eV