JEE Physics - MCQ Practice Questions

Which of the following statements about the photoelectric effect is correct?

In Bohr's model of hydrogen atom, the angular momentum of electron in the nth orbit is:

An electron in the first excited state of hydrogen atom (n=2) transitions to ground state (n=1). The wavelength of emitted photon is approximately:

The de Broglie wavelength of an electron with kinetic energy 50 eV is:

In Compton scattering, a photon collides with a free electron at rest. Which quantity always increases?

If the binding energy per nucleon of ⁵⁶Fe is 8.79 MeV and that of ²³⁵U is 7.59 MeV, which nucleus is more stable?

A ²¹⁰₈₄Po nucleus undergoes alpha decay. The resulting nucleus is:

The activity of a radioactive sample decreases from 8000 Bq to 1000 Bq in 20 hours. The half-life of the sample is:

X-rays are produced when high-speed electrons strike a metal target. This is an example of:

In a nuclear reactor, control rods are used to absorb neutrons. Which isotope is commonly used in control rods?

A radioactive nucleus ₆₀₂₇Co undergoes beta-plus decay. The daughter nucleus is:

The threshold frequency for photoelectric effect in a metal is 6 × 10¹⁴ Hz. The work function of the metal is:

According to the uncertainty principle, if the position of an electron is known with uncertainty Δx = 10⁻¹⁰ m, the minimum uncertainty in momentum is:

When ²³⁵U nucleus undergoes fission, the total mass defect is 0.1 u. The energy released is approximately:

The intensity of characteristic X-rays depends on:

An electron transitions from n=3 to n=1 in a hydrogen atom. How many distinct spectral lines can be observed from all possible transitions?

In pair production, a photon with energy 3 MeV converts near a nucleus into an electron-positron pair. The rest mass energy of electron/positron is 0.51 MeV. The excess energy appears as:

The half-life of ¹⁴C is 5730 years. A sample contains 1 mg of ¹⁴C. After 11,460 years, the remaining mass will be:

For a nucleus, the neutron-to-proton ratio (N/Z) increases with mass number. This is because:

A photon of wavelength 100 pm strikes a stationary free electron. After Compton scattering at an angle of 60°, the wavelength of the scattered photon is found to be 102.4 pm. What is the kinetic energy of the recoil electron? (Given: h = 6.63 × 10⁻³⁴ J·s, c = 3 × 10⁸ m/s, mₑ = 9.1 × 10⁻³¹ kg)