NEET Modern Physics MCQs & PYQs

Electrons used in a electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased to 100 kV then the de Broglie wavelength associated with the electrons would:

(2011 Pre)

A radioactive nucleus of mass M emits a photon of frequency $\nu$ and the nucleus recoils. The recoil energy will be:

(2011 Pre)

A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of $3 \times 10^6 ms^{-1}$. The velocity of the particle is (mass of electron = $9.1 \times 10^{-31} kg$):

(2008)

If particles are moving with same velocity, then de-Broglie wavelength is maximum for:

(2002)

The K.E. of electron and photon is same then relation between their De-Broglie wavelength:

(1999)

An electron beam has a kinetic energy equal to 100 eV. Find its wavelength associated with a beam, if mass of electron = $9.1 \times 10^{-31} kg$ and $1 eV = 1.6 \times 10^{-19} J/eV$. (Planck’s constant = $6.6 \times 10^{-34} Js$).

(1996)

An electron of mass m, when accelerated through a potential difference V, has de-Broglie wavelength $\lambda$. The de-Broglie wavelength associated with a proton of mass M accelerated through the same potential difference, will be

(1995)

The de Broglie wavelength of an electron moving with kinetic energy of 144 eV is nearly,

(2020-Covid)

An electron is accelerated through a potential difference of 10,000 V. Its de Broglie wavelength is, (nearly) : ($m_e = 9 \times 10^{-31} kg$)

(2019)

An electron of mass m with an initial velocity $\vec{v} = v_0\hat{i} (v_0 > 0)$ enters an electric field $\vec{E} = -E_0\hat{i} (E_0 = constant > 0)$ at t = 0. If $\lambda_0$ is its de-Broglie wavelength initially, then its de-Broglie wavelength at time t is

(2018)