A particle of mass 1mg has the same wavelength as an electron moving with a velocity

⇦

⇨

A particle of mass 1mg has the same wavelength as an electron moving with a velocity of 3 x 10⁶ ms⁻¹. The velocity of the particle is: (mass of electron = 9.1 x 10⁻³¹ kg)

Options

(a) 2.7 x 10⁻¹⁸ ms⁻¹
(b) 9 x 10⁻² ms⁻¹
(c) 3 x 10⁻³¹ ms⁻¹
(d) 2.7 x 10⁻²¹ ms⁻¹

Correct Answer:

2.7 x 10⁻²¹ ms⁻¹

Explanation:

Wavelength of particle (λ₁)
= h/mv = h / (1 x 10⁻³) x v
where v is the velocity of the particle. Wavelength of electron
(λ₂) = h / (9.1 x 10⁻³¹) x (3 x 10⁶)
But λ₁ = λ₂
h / (1 x 10⁻³) x v = h / (9.1 x 10⁻³¹) x (3 x 10⁶)
v = (9.1 x 10⁻³¹) x (3 x 10⁶) / 10⁻³
= 2.7 x 10⁻²¹ ms⁻¹

Related Questions:

1. The length of an elastic string is a metre when the longitudinal tension is 4N and b
2. Assertion(A) :The change in kinetic energy of a particle is equal to the work done
3. A particle starting from the origin (0, 0) moves in a straight line in the (x, y) plane
4. A 0.5 kg ball moving with a speed of 12 m/s strikes a hard wall at an angle
5. Hydrogen atom in ground state is excited by a monochrmatic radiation of λ=975 Å

Topics: Dual Nature of Matter and Radiation (150)
Subject: Physics (2479)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends