2003 Physics. Advanced Higher. Finalised Marking Instructions

Transcription

1 003 Physics Advanced Higher Finalised Marking Instructions

2 Scottish Qualifications Authority Detailed Marking Instructions Advanced Higher Physics 003. General Marking Instructions SQA published Physics General Marking Instructions in July 999. Please refer to this publication when interpreting the detailed marking instructions that follow.. Recording of marks The following additional advice was given to markers regarding the recording of marks on candidate scripts. (a) (b) (c) (d) (e) (f) (g) The total mark awarded for each question should be recorded in the outer margin. The inner margin should be used to record the mark for each part of a question as indicated in the detailed marking instructions. The fine divisions of marks shown in the detailed marking scheme may be recorded within the body of the script beside the candidate s response. Where such marks are shown they must total to the mark in the inner margin. Numbers recorded on candidate scripts should always be the marks being awarded. Negative marks or marks to be subtracted should not be recorded on scripts. The number out of which a mark is scored should never be recorded as a denominator. (½ mark will always mean one half mark and never out of ) Where square ruled paper is enclosed inside answer books it should be clearly indicated that this item has been considered by the marker. The mark awarded should be transferred to the script booklet inner margin and marked G. The mark awarded for each question should be transferred to the grid on the back of the script. When the marker has completed marking the candidate s response to all questions, the marks for individual questions are added to give the total script mark. The total mark awarded for an individual question may include an odd half mark ½. If there is an odd half mark in the total script mark, this is rounded up to the next whole number when transferred to the box on the front of the script. Page two

3 . (a)(i) 003 Physics Advanced Higher s = ut + /at ( /) (u = 0) s = /at ( /) a = s/t 3 t =. 45(s) ( /) a = ( 3. 54). 45 a =. 8 m s ( /) (iii) Uncertainty = (±) t max t min n ( /) Deduct ( /) if % wrongly calculated. = (±) ( /) = (±) s () (= ±. 45%) (iv) TIME % Uncertainty = 0. 06/. 45 =. 45% ( /) % Uncertainty in t = 4. 9% ( /) Accept. 4% Accept 5% DISTANCE % Uncertainty = 0. 0/3. 54 = 0. 8% ( /) ignore Uncertainty in a = 4. 9% ( /) (v) Accept 5% Uncertainty = = ( /) 00 a = (. 8 ± 0. 06)(m s ) ( /) Page three

4 003 Physics Advanced Higher. (b)(i) a = v r ( /) a = ( /) a = 9. 0ms () F radial = mv r ( /) 6 F radial =. 5 4 ( /) F radial =. 5 (N) ( /) (Radial) force sufficient to provide this (or equivalent) ( /) (c) Component of reaction now acts radially () Central force increased () Diagram acceptable for first mark. F central F reaction Page four

5 003 Physics Advanced Higher. (a) 3 I = mr () (b) I = () (= kgm ) (c)(i) T = Fr ( /) = ( ) ( /) Resultant T = ( ) ( /) = N m ( /) T = Iα ( /) α = / ( /) α = rad s () (iii) N of revolutions = cord length/circumference ( /) = 0. 5/( π ) ( /) = 9. 9 ( /) Accept = 5 rad () (iv) θ = N of revolutions π θ = 9. 9 π ( /) θ = 5 rad ω = ω o + αθ ( /) ω = ( /) ω = rad s () (v) α = T/I ( /) α = ( )0. 07/0. 06 α = ( ). (rad s ) ( /) α = (ω ω o )/t ( /) t = (4. )/. ( /) t = 5. 7s () (. 4. ) used max ( /) Page five Accept 6 rad if No of revolutions = 0 θ = ω o t + /αt (ω = ω o + αt) Both equations required for this ( /) t =. 4s ( /) ω = rad s () Accept. rad s Accept. 7 rad s a = (ω o ω)/t (0)WP ( /) for sign error. taken, t = 5. 8s α =. 7, t = s All acceptable 3

6 3. (a) 003 Physics Advanced Higher Shape () Direction ( /) Correct lack of symmetry ( /) 8 (b)(i) (A) Ep = (GM M )/r ( /) ( /) ( /) = ( ) = J ( /) No negative WP (0) G = ( /) M = ( /) (B) Ep = ( ) ( /). 0 6 = J ( /) 3 (b) E k = ( ) ( ) ( /) E k = J ( /) (b)(iii) E k = /mv ( /) v = ( 0 7 /5) ( /) v = ( ) v =. x 0 3 ms () Accept J Accept. x 0 3 ms if E k = J is taken Page six

7 003 Physics Advanced Higher 4. (a) F spring = weight of mass 6 F spring = mg ( /) F spring = F spring = 5 N ( /) Accept 4. 7N (b)(i) F spring = (70 5)/40 ( /) F spring = 6. 5 (N) ( /) F UN = F spring W F UN = F UN = N () F = ( )kx ( /) ( ) F k = =. ( /) 3 = 36 8 x 40 0 Sub N () Accept. 5 N OR consistent with (a) Alternative Solution 40 mm N ( /) 30 mm (5 30) 40 ( /) = N () (b) F UN = ( ) mω x ( /) ω = /( ) ( /) ω = 44 ω = 5. 6 (rad s ) ( /) T = π/ω ( /) T = 0. 40s () Accept rad s T = π m k ( /) k () Sub ( /) T = s () 3 Page seven

8 5. (a) 003 Physics Advanced Higher (b)(i) Force per unit positive charge () F = QE ( /) = ( /) ( = N) Must have unit AND positive. (,0) (b) (c)(i) a = F/m ( /) a = (. 0 6 )/( ) ( /) a = ms v = u + as ( /) v = ( /) v = v = ms () m =. 3 (9 0 ) 8 (. 5 0 ) ( 8 ) ( ) ( /) top DATA ( /) Subst. Accept QV = /mv ( /) V = Ed = = ( /) v = (QV/m) = ( ) v = ms () m = kg () Accept kg E = mc ( /) E = ( ) ( /) E = J () M = kg gives E = J (d) V = Q/(4πε 0 r) ( /) E k = (Q Q )/(4πε 0 r) () E k = QV ( /) ( /) ( /) r = ( ) (4 π ) ( /) ( /) r = m () 3 Page eight

9 003 Physics Advanced Higher 6. (a) 7 F = BIl(sinθ) ( /) F = ( /) F = N () (b) T = Fr ( /) T = ( /) T = Fr alone ( /) only. T = Nm () (c) ( /) ( /) T = cos30 T = Nm () (d) (Plane of) the loop is always parallel to the magnetic field. or Force will always act perpendicular to (the plane of) the loop. Idea of radial field. () () Page nine

10 7. (a) 003 Physics Advanced Higher B = µ o I/πr ( /) B = (4π ) (π 0. ) ( /) 5 B = T () (b) F/l = µ 0 I I /πr ( /) F/l = ( /) F/l = Nm () Accept F/l = BI ( /) Accept Nm Force is repulsive or Force acts to the right () 3 Page ten

11 003 Physics Advanced Higher 8. (a)(i) 7 Force due to magnetic field and force due to electric field are balanced. () F = QE ( /) F = QvB ( /) v = E/B v = ( )/( ) v = ms () ( /) for balanced. ( /) for names of forces. v = E/B () (b) Speed of alphas equal to speed of electrons. () Speed of charged particles depends only on E and B OR Speed does not depend on Q or m () (c) Path of α has greater radius of curvature than path of electron () Paths in opposite directions ( /) Paths in correct directions ( /) α Electron Page eleven

12 003 Physics Advanced Higher 9. (a)(i) 0 A changing/increasing current in the inductor generates a back e.m.f. () R = V/I R = /0. 5 ( /) top and ( /) bottom R = 8 Ω () e.m.f. = ( ) LdI dt ( /) L = /0 ( /) L = 0. 0 H () E = V required L= 0. 0 H ( / max) (iv) E = /LI ( /) E = / ( /) E = J () (b) V reading increases ( /) Inductive reactance increases (or equivalent) () Current decreases (V = IR) () so V reading decreases ( /) Idea of conservation of energy acceptable ie as V increases V decreases 3 Page twelve

13 003 Physics Advanced Higher 0.(a) 7 Amplitude = 5 mm () (b) f = 55 (Hz) ( /) λ = 6 (mm) ( /) v = fλ ( /) v = 55 6 ( /) v = 880 mm s (c) (v = m s ) () φ = πx/λ ( /) φ = π 4/6 ( /) φ = 3π rad () (d) Any multiple of 6 mm () Accept 6 mm π 4 mm π 4/6 = 3π rad. 5 λ ( /) only. Must be in radians 3 Page thirteen

14 .(a)(i) 003 Physics Advanced Higher Constant phase difference/relationship between sources () 7 Optical path difference = Path difference n () (iii) (A) Optical p.d. = (n + /)λ ( /) (B) Optical p.d. = n λ ( /) (iv) There will be a phase change of π at the lower surface of the slide. () λ unacceptable (b)(i) Rays reflected from the surface of MgF interfere destructively with rays reflected from the glass surface. () d = λ/4n ( /) d = ( ) data ( /) d = m () Page fourteen

15 .(a) 003 Physics Advanced Higher Polarised Light (The electric field vector of) the wave oscillates in one plane. 5 Unpolarised Light (The electric field vector of) the wave oscillates in many planes. () (b) B Less than 5(W m ) More than Zero ( /) C Zero ( /) D Less than 5(W m ) More than Zero ( /) Units not required as given in table heading. E 5(W m ) ( /) (c) n = sin i p sinθ glass ( /) i p + θ glass = 90 θ glass = 90 i p ( /) n glass sin i p = sin(90 i p) ( /) n glass = sin i p cos i p ( /) n glass = tan i p [END OF MARKING INSTRUCTIONS] Page fifteen