PHYSICS7 - FORM 0 [1] The work function of copper is 4.7...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
FORM 0 [1] The work function of copper is 4 . 7eV. Electrons are emitted in the photoelectric effect if the wavelength of the incident light is [A] more than the threshold wavelength of 1 . 14 × 10 15 nm. [B] less than the threshold wavelength of 1 . 14 × 10 15 nm. [C] less than the threshold wavelength of 264nm. [D] less than the threshold wavelength of 1 . 14 × 10 15 Hz. [E] more than the threshold wavelength of 264nm. [2] A 1 W monochromatic light source emits orange light of wavelength 620nm. About how many photons per second are emitted by the source? [A] 3 . 1 × 10 18 [B] 6 . 2 × 10 18 [C] 2 [D] 3 . 2 × 10 - 19 [E] 0.5 [3] Electrons are accelerated with a voltage of 60 , 000V. The accelerated electrons hit a metal target. The most energetic photons emitted are [A] γ rays with an energy of 60,000 electron Volts. [B] X rays with an energy of 30,000 electron Volts [C] X rays with an energy of 60,000 electron Volts [D] X rays with an energy of 60,000 Joules [4] Two stars are at rest with respect to each other. Observersin the stars observe an astronaut fly from one star to the other with a speed of v =0 . 9 c in a time of 20 years. How long did the trip last as measured by the astronaut? [A] 8.7 years
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/10/2011 for the course PHYS 100 taught by Professor Razasuleman during the Spring '10 term at University of Engineering & Technology.

Page1 / 3

PHYSICS7 - FORM 0 [1] The work function of copper is 4.7...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online