Heisenberg's Uncertainty Principle
Trending Questions
Q.
What is De Broglie Hypothesis?
Q. If uncertainty in position and momentum are equal, then uncertainty in velocity is eqaul to:
- 1m×√hπ
- hπ
- 12m×√hπ
- √h2π
Q.
What is Schrodingers Law
Q. Uncertainty in position of a 0.25 g particle is 10−5. Uncertainty in velocity of that particle is:
(h=6.6×10−34J s)
(h=6.6×10−34J s)
- 1.2×10−34 ms−1
- 2.1×10−25 ms−1
- 1.6×10−29 ms−1
- 1.7×10−9 ms−1
Q. If uncertanity in the measurement of position and momentum are equal, calculate uncertainity in the measurement of velocity:-
- Δv=1π√h2m
- Δv=12π√h2m
- Δv=12m√hπ
- Δv=1m√h2π
Q. An atom typically exists in an excited state for about Δt=10−8 s. Estimate the uncertainity in frequency Δν in the frequency of emitted photons when an atom makes a transition from an excited state with the simultaneous emission of a photon with an average frequency of νav = 7.1×1014 Hz. Calculate the ratio of uncertainity in frequency to the average frequency.
- 1.12×10−10
- 2.11×10−10
- 2.11×10−8
- 1.12×10−8
Q.
Who came up with the uncertainty principle?
Q. Calculate the uncertainity in velocity of a cricket ball of mass 150 g if the uncertainty in its position is of the order of 1 oA.
(h=6.6×10−34kgm2s−1)
(h=6.6×10−34kgm2s−1)
- 3.5×10−24m s−1
- 5.809×10−24m s−1
- 9.077×10−24m s−1
- 1.908×10−24m s−1
Q. Both velocity and position of an electron can be determined simultaneously.
- True
- False
Q. If an electron has a wavelength λ and it has an uncertainty in its kinetic energy equal to ΔE, then what will be uncertainty in its position?
- h24πmλΔE
- h4πmλΔE
- h4πλΔE
- h24πλΔE
Q. The lifetime of an excited state of an atom is 3×103 s. What will be the minimum uncertainity in the Energy?
- 1.76×10−35 J
- 1.76×10−34 J
- 1.76×10−33 J
- 1.76×10−38 J
Q.
A golf ball has a mass of 40g and a speed of 45 ms−1. If the speed can be measured with an accuracy of 2%, calculate the uncertainty in the position.
1.46 × 10−33 m
2.62 × 10−34 m
7.84 × 10−35 m
5.55 × 10−33 m
Q. In an atom, an electron is moving with the speed of 600 m/s have an accuracy of 0.005%. The minimum uncertainity with which the position of the electron can be located is:
h=6.6×10−34 Js, mass of electron, em=9.1×10−31 kg
h=6.6×10−34 Js, mass of electron, em=9.1×10−31 kg
- 5.10×10−3 m
- 1.92×10−3 m
- 3.84×10−3 m
- 1.52×10−3 m
Q. Bohr's idea of electrons moving around the nuclei in well defined paths is not valid due to which of the following phenomena?
- Zeeman effect
- Stark effect
- Heisenberg's Uncertainity Principle
- Line spectrum of hydrogen atom
Q. The uncertainty principle and the concept of wave nature of matter were proposed by _____ and _____, respectively.
- de-Broglie and Heisenberg
- Heisenberg and de-Broglie
- Max planck and Avogadro
- None of the above
Q. The uncertainty in the position of a ball weighing 50 g is ±10−4 mm. Calculate the minimum uncertainty in its velocity in m/s
- 2.63×10−29 m/s
- 1.05×10−26 m/s
- 4.5×10−30 m/s
- 7.55×10−29 m/s
Q.
A green ball weighs 80 g and comes travelling towards you at 900 m/s. A photon of light emitted from green ball has a wavelength of 6×10−7 m. Assuming that the error in the position of ball is the same as the wavelength of its photon, calculate error in the momentum (kgm/s) of the green ball.
- 1.054×10−30
- 1.054×10−23
- 2.786×10−23
- 8.75×10−29
Q. A green ball weighs 75 g and comes travelling towards you at 400 cm/s. A photon of light emitted from green ball has a wavelength of 5×10−5 cm. Assuming that the error in the position of ball is the same as the wavelength of itself, calculate the error in the momentum of the green ball.
- 1.054×10−30kg cm/s
- 1.054×10−23g cm/s
- 2.786×10−23g m/s
- 2.786×10−30g cm/s
Q. If the uncertainty in the position of an electron is zero, the uncertainty in its momentum will be
- zero
- infinite
- h2π
Q.
Uncertainity in position of a hypothetical subatomic particle is 1Å and uncertainty in velocity is 3.34π × 105 m/s then the mass of the particle is approximately [h = 6.6 × 10−34 Js]
2 × 10−28 kg
2 × 10−27 kg
2 × 10−29 kg
2 × 10−26 kg
Q. Uncertainty in the position of an electron (mass = 9.1×10−31 kg) moving with a velocity of 100 m/s accurate upto 0.0001% will be:
- 5.79 m
- 0.579 m
- 5.79×10−2 m
- 5.79×10−3 m
Q. Uncertainty in the position of an electron (mass = 9.1×10−31 kg) moving with a velocity of 100 m/s accurate upto 0.0001% will be:
- 5.79 m
- 0.579 m
- 5.79×10−2 m
- 5.79×10−3 m
Q.
A golf ball has a mass of 40g and a speed of 45 ms−1. If the speed can be measured with an accuracy of 2%, calculate the uncertainty in the position.
1.46 × 10−33 m
2.62 × 10−34 m
7.84 × 10−35 m
5.55 × 10−33 m
Q.
In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005 %. Certainity with which the position of the electron can be located is
(h = 6.6 × 10−34 kg m2 s−1, mass of electron, em = 9.1 × 10−31 kg)
5.10 × 10−3 m
1.92 × 10−3 m
3.84 × 10−3 m
1.52 × 10−4 m
Q. Calculate the uncertainity in velocity of a cricket ball of mass 150 g if the uncertainty in its position is of the order of 1 oA.
(h=6.6×10−34kgm2s−1)
(h=6.6×10−34kgm2s−1)
- 3.5×10−24m s−1
- 5.809×10−24m s−1
- 9.077×10−24m s−1
- 1.908×10−24m s−1
Q. If uncertainty in position and momentum of a particle are numerically equal, then the uncertainty in the speed of the particle should be:
- √h2π
- 12m√hπ
- √h2π
- 12m√h2π
Q. What is the maximum precision with which the momentum of an electron can be known if the uncertainity in the position of electron is ±0.001 ∘A? Will there be any problem in describing the momentum if it has a value h2πa0, where a0 is Bohr's radius of first orbit, i.e., 0.529 ∘A.
- The uncertainity in momentum seems to be about 263.5 times as large as the momentum itself is.
- The uncertainity in momentum seems to be about 243.5 times as large as the momentum itself is.
- The uncertainity in momentum seems to be about 273.5 times as large as the momentum itself is.
- none of the above
Q. In an atom, an electron is moving with a speed of 250 m/s which is measured with an accuracy of 0.001 %. Certainty with which the position of the electron can be located is:
(h=6.6×10−34 kg m2 s−1, Mass of electron=9.1×10−31 kg)
(h=6.6×10−34 kg m2 s−1, Mass of electron=9.1×10−31 kg)
- 1.52×10−4m
- 5.1×10−3m
- 2.30×10−3m
- 3.84×10−3m
Q. Alveoli are tiny sacs in the lungs whose average diameter is 5×10−10 m. Consider an oxygen molecule (5.3×10−26 kg) trapped within an alveolus. Calculate the uncertainty in the velocity of the oxygen molecule.
- 2.05 ms−1
- 1.20 ms−1
- 0.20 ms−1
- 1.50 ms−1
Q. If uncertanity in the measurement of position and momentum are equal, calculate uncertainity in the measurement of velocity:-
- Δv=1π√h2m
- Δv=12π√h2m
- Δv=12m√hπ
- Δv=1m√h2π
