NEET UG Modern Physics — practice questions
25 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice NEET UG Modern Physics in the app →A metal is illuminated with light of frequency less than its threshold frequency. Which outcome is correct?The series of hydrogen lines lying entirely in the ultraviolet region is the:The hydrogen series lying in the visible region is the:The Rydberg formula for hydrogen lines is 1/λ = R(1/n₁² − 1/n₂²) where for the Balmer series n₁ equals:The Rydberg constant R for hydrogen is approximately:For hydrogen-like ions of atomic number Z, the energy of the n-th level is:The orbital speed of the electron in the n-th Bohr orbit is proportional to:The total energy of an electron in a Bohr orbit equals:De Broglie supported Bohr's quantisation by suggesting that the electron orbit must contain an integer number The angular momentum L of the electron in the n-th Bohr orbit is:In the visible-region Balmer series, the longest-wavelength line corresponds to the transition:In Bohr's model, an electron in a stationary orbit:Bohr's model could explain the hydrogen spectrum but failed to:The wavelength of a photon emitted when an electron in hydrogen jumps from n = 3 to n = 2 is approximately:Number of spectral lines emitted when a hydrogen atom de-excites from n = 4 to n = 1 (all possible cascades) iThe energy required to excite a hydrogen atom from the ground state to its first excited state (n = 1 to n = 2In Bohr's model, the centripetal force on the electron is supplied by the:The de Broglie wavelength of an electron in the n = 1 Bohr orbit of hydrogen equals the:For the ground state of singly ionised helium (He⁺, Z = 2), the energy of the electron is:The difference between the incident energy and threshold energy for an electron in a photoelectric effect expeA waveform shown when applied to the following circuit will produce which of the following output waveform. AsThe figure shows the variation of photocurrent with anode potential for a photo-sensitive surface for three diA radioactive sample consists of two distinct species having equal number of atoms initially. The mean life tiThe following diagram indicates the energy levels of a certain atom when the system moves from $4E$ level to $The de-Broglie wavelength associated with a particle of mass $10^{-6}$ kg with a velocity of $10 \, ms^{-1}$ i