61.

What wavelength must electromagnetic radiation have if a photon in the beam has the same momentum as an electron moving with a speed 1.1 x 10⁵ m/s (Planck's constant = 6.6 x 10^-34 J-s, rest mass of electron = 9 x 10^-31 kg ?

• 2/3 nm

• 20/3 nm

• 4/3 nm

• 40/3 nm

Huygens' wave theory of light cannot explain

• Diffraction phenomena

• Interference  phenomena 

• Photoelectric effect

• Polarization of light

An electron, a neutron and an alpha particle have same kinetic energy and their de-Broglie wavelength are λ_e, λ_n, λ_α and respectively. Which statement is correct about their de-Broglie wavelengths ?

• λ_e > λ_n > λ_α

• λ_e < λ_n > λ_α

• λ_e < λ_n < λ_α

• λ_e > λ_n < λ_α

It takes 4.6 eV to remove one of the least tightly bound electrons from a metal surface. When monochromatic photons strike the metal surface, electrons having kinetic
energy from zero to 2.2 eV are ejected. What is the energy of the incident photons ?

• 2.4 eV

• 2.2 eV

• 6.8 eV

• 4.6 eV

In an insulator, band gap of the order of

• 0.1 eV

• 1 eV

• 5 eV

• 100 eV

For a P-N junction diode

• Forward current in mA and reverse current is in µA

• Forward current is in µA are reverse current is in mA

• Both forward and reverse currents are in µA

• Both forward and reverse currents are in mA

For a Zener diode

• both p and n regions are heavily doped

• p region is heavily doped but n region is lightly doped

• n region is heavily doped but p region is lightly doped

• both p and n regions are lightly doped

Speech signals is in the range of

• 3700 Hz to 7000 $\stackrel{\circ }{\mathrm{A}}$ wavelength

• 20 Hz to 20 kHz frequency

• 300 Hz to 3100 Hz frequency

• 540 kHz to 1600 kHz frequency

To transmit a signal of frequency ω_m with a carrier frequency ω_c, in AM transmission, the bandwidth of the filter and amplifier is

• ω_m

• 2ω_m

• ω_c

• ω_c − ω_m

Which of the following particle when bombards on ⁶⁵Cu will turn into ⁶⁶Cu ?

• Proton

• Neutron

• Electron

• Alpha particle