Heisenberg’s Uncertainty Principle

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Heisenberg’s Uncertainty Principle: Overview

This Topic covers sub-topics such as Heisenberg Uncertainty Principle and Significance of Heisenberg Uncertainty Principle

Important Questions on Heisenberg’s Uncertainty Principle

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 1

The measurement of the electron position if associated with an uncertainty in momentum which is equal to 1× 10 −18 g cm  s −1 . The uncertainty in electron velocity is,

(mass of an electron is   9× 10 −28 g )

                                                                                                                                                                                                                               

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 2

If uncertainty in position and momentum are equal, then uncertainty in velocity is :

                                                                                                                                                                                                                               

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 3

Given : The mass of electron is  9.11×10−31 kg, Planck constant is  6.626×10−34 Js, the uncertainty involved in the measurement of velocity within a distance of   0.1 Å is

                                                                                                                                                                                                                               

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 4

The position of both, an electron and a helium atom is known within 1.0 nm. Further, the momentum of the electron is known with in 5.0×10−26kg ms−1.The minimum uncertainty in the measurement of the momentum of the helium atom is

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 5

The position of both, an electron and a helium atom is known within 1.0 nm. Further the momentum of the electron is known within    5.0× 10 −26 kg m s −1 .  The minimum uncertainty in the measurement of the momentum of the helium atom is

                                                                                                                                                                                                                               

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 6

The mathematical expression of the uncertainty principle is

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 7

The exact path of electron in any orbital camot be determined. The above statement is based on         

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 8

Calculate the mass of an elementary particle, which is accelerated to twice the velocity of light with the precision ±1% and has 1.05×10-13 m uncertainty in position. h=6.6×10-34 kg m2 s-1

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 9

If the uncertainty in momentum and uncertainty in the position of a particle are equal, then the uncertainty in its velocity would be given by _____

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 10

Find the uncertainty in the position of an electron which is moving with a velocity of 2.99x104 cm·s-1, accurate up to 0.0016%. (Given, me=9.1×10-28 g,h=6.626×10-27erg.s

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 11

If a proton is accelerated to a velocity of 3×107 m·s-1 which is accurate up to ±0.5%, then the uncertainty in its position will be [mass of proton =1.66×10-27 kg,h=6.6×10-34 J.s

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 12

If the position of the electron is measured within an accuracy of ±0.002 nm. What is the uncertainty in the momentum of the electron.

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 13

What is the uncertainty in position of an electron if uncertainty in its velocity is 0.001%. Planck's constant h=6.62×10-34 Js.

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 14

The uncertainty in the position and velocity of a particle are 10-10 m and 5.27 x 10-24 ms-1 respectively. What is the mass of the particle. (h=6.625 x 10-34 Js).

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 15

A ball weighing 10 g is moving with a velocity of 90 ms-1. If the uncertainty in its velocity is 5% then the uncertainty in its position is _______ ×10-33 m. (Rounded off to the nearest integer) [Given : h=6.63×10-34 Js]

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 16

According to Heisenberg uncertainty principle, which two quantities cannot be accuracy measured together at the same instant of time?

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 17

According to Heisenberg uncertainty principle, which two quantities cannot be accuracy measured together at the same instant of time?

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 18

For which of the following cases, the effect of Heisenberg uncertainty principle has significant consequences?

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 19

An object having mass 50 g is moving with velocity 200 ms-1. If the percentage error in velocity measurement is 0.2%, the uncertainty in its position will be?

h=6.4×10-34Js.and π=3.2

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chemistry>Atomic Structure>Heisenberg’s Uncertainty Principle> Q 20

What would be the uncertainty in position for an electron (mass =9.1×10-28 gm), if it moves with a velocity 3.0×104 cm s-1 [precision 0.011%] :