Complete , verified & rated OCR A A-Level
Physics Paper 2
Describe How Ultrasound Scanning Is Used To Obtain Diagnostic Information About Internal
Structures Of A Body.
-Pulses Of Ultrasound (Sent Into The Body)
-Wave / Ultrasound / Pulse / Signal Is Reflected (At Boundary Of Tissue)
-Time Of Delay Used To Determine Depth / Thickness
-The Fraction Of Reflected Signal Is Used To Identify The
Tissue
Describe The Piezoelectric Effect
The Application Of A P.D. Across A Material / Crystal Causes
An Expansion / Contraction / Vibration
Describe The Differences Between An A-Scan And A
B-Scan
-A-Scan In One Direction Only / Range Or Distance Or Depth
Finding
-B-Scan Uses A Number Of Sensors Or A Sensor In Different
Positions / Angles (To Build Up A 2D/3D Image)
,Alpha-Particle Scattering Experiment Is...
Evidence Of A Small, Charged Nucleus
Simple Nuclear Model Of The Atom...
The Atom Is Mostly Space With A Very Small, Very Dense Positively Charged Nucleus And
Negatively Charged Electrons Located In The Atomic Space.
The Relative Size Of The Nucleus Of An Atom Is...
10^-15 (Metres)
The Relative Size Of An Alpha Particle Is...
10^-10 (Metres)
The Strong Nuclear Force...
Acts Between All Nucleons. It Is A Short Range Force, Effective Over A Few Femtometres.
Attractive Above (Approx.) 3fm And Repulsive Below (Approx.) 0.5fm.
Radius Of A Nucleus
R = R0 A^(1/3), In Which R0 Is A Constant And A Is The Nucleon Number
Rutherford Gold Foil Experiment Procedure
Pointed A Beam Of Alpha Particles At A Thin Foil Of Metal And Measured The Scattering Pattern
By Using A Fluorescent Screen.
, Rutherford Gold Foil Experiment Findings
1. They Spotted Alpha Particles Bouncing Off The Metal Foil In All Directions, Some Right Back At
The Source.
2. Only Very Few Were Deflected By Large Amounts (>90 Degrees)
Rutherford Gold Foil Experiment Conclusions
1. The Atom's Positive Charge Was Concentrated In A Much Tinier Volume Than Thomson
Imagined.
2. Tiny Spheres Of Intense Positive Charge Were Separated By Vast Gulfs Of Empty Space.
X-Ray
Electromagnetic Radiation With Wavelength Ranging From 0.1 To 10 Nanometres
X-Ray Tube
A Piece Of Equipment That Produces X Ray Photons By Firing Electrons From A Beta Cathode
Across A Large PD In An Evacuated Tube-X Ray Photons Are Produced When The Electrons Are
Decelerated By Hitting The Target Metal Of The Anode.
Thermionic Emission
The Release Of Electrons From The Surface Of A Heated Material
Attenuation
The Decrease Of Intensity Of Electromagnetic Radiation As It Passes Through Matter And/Or
Space
Physics Paper 2
Describe How Ultrasound Scanning Is Used To Obtain Diagnostic Information About Internal
Structures Of A Body.
-Pulses Of Ultrasound (Sent Into The Body)
-Wave / Ultrasound / Pulse / Signal Is Reflected (At Boundary Of Tissue)
-Time Of Delay Used To Determine Depth / Thickness
-The Fraction Of Reflected Signal Is Used To Identify The
Tissue
Describe The Piezoelectric Effect
The Application Of A P.D. Across A Material / Crystal Causes
An Expansion / Contraction / Vibration
Describe The Differences Between An A-Scan And A
B-Scan
-A-Scan In One Direction Only / Range Or Distance Or Depth
Finding
-B-Scan Uses A Number Of Sensors Or A Sensor In Different
Positions / Angles (To Build Up A 2D/3D Image)
,Alpha-Particle Scattering Experiment Is...
Evidence Of A Small, Charged Nucleus
Simple Nuclear Model Of The Atom...
The Atom Is Mostly Space With A Very Small, Very Dense Positively Charged Nucleus And
Negatively Charged Electrons Located In The Atomic Space.
The Relative Size Of The Nucleus Of An Atom Is...
10^-15 (Metres)
The Relative Size Of An Alpha Particle Is...
10^-10 (Metres)
The Strong Nuclear Force...
Acts Between All Nucleons. It Is A Short Range Force, Effective Over A Few Femtometres.
Attractive Above (Approx.) 3fm And Repulsive Below (Approx.) 0.5fm.
Radius Of A Nucleus
R = R0 A^(1/3), In Which R0 Is A Constant And A Is The Nucleon Number
Rutherford Gold Foil Experiment Procedure
Pointed A Beam Of Alpha Particles At A Thin Foil Of Metal And Measured The Scattering Pattern
By Using A Fluorescent Screen.
, Rutherford Gold Foil Experiment Findings
1. They Spotted Alpha Particles Bouncing Off The Metal Foil In All Directions, Some Right Back At
The Source.
2. Only Very Few Were Deflected By Large Amounts (>90 Degrees)
Rutherford Gold Foil Experiment Conclusions
1. The Atom's Positive Charge Was Concentrated In A Much Tinier Volume Than Thomson
Imagined.
2. Tiny Spheres Of Intense Positive Charge Were Separated By Vast Gulfs Of Empty Space.
X-Ray
Electromagnetic Radiation With Wavelength Ranging From 0.1 To 10 Nanometres
X-Ray Tube
A Piece Of Equipment That Produces X Ray Photons By Firing Electrons From A Beta Cathode
Across A Large PD In An Evacuated Tube-X Ray Photons Are Produced When The Electrons Are
Decelerated By Hitting The Target Metal Of The Anode.
Thermionic Emission
The Release Of Electrons From The Surface Of A Heated Material
Attenuation
The Decrease Of Intensity Of Electromagnetic Radiation As It Passes Through Matter And/Or
Space
