امواج، بصریات اور جدید طبیعیات

In Young's double slit experiment, if the wavelength of light is doubled, the fringe spacing:

• 1 Halves
• 2 Doubles
• 3 Stays the same
• 4 Becomes zero

Two tuning forks of 256 Hz and 260 Hz are sounded together. What is the beat frequency?

• 1 516 Hz
• 2 4 Hz
• 3 2 Hz
• 4 258 Hz

If the momentum of a particle is doubled, its de Broglie wavelength:

• 1 Doubles
• 2 Is halved
• 3 Stays the same
• 4 Becomes four times larger

A metal has a work function of 2 eV and is lit by photons of 5 eV. What is the maximum kinetic energy of the emitted electrons?

• 1 7 eV
• 2 2 eV
• 3 5 eV
• 4 3 eV

What is the fundamental frequency of a pipe of length 0.5 m closed at one end? (Speed of sound 340 m/s)

• 1 340 Hz
• 2 170 Hz
• 3 680 Hz
• 4 85 Hz

A sample has 800 radioactive nuclei. How many remain undecayed after 2 half-lives?

• 1 400
• 2 200
• 3 100
• 4 600

Polarisation of light shows that light is:

• 1 A longitudinal wave
• 2 A transverse wave
• 3 A particle only
• 4 A sound wave