CJC 2024.H2.Phy.PRELIM.P2 - QP

CANDIDATE NAME CLASS 2T PHYSICS 9749/02 Paper 2 Structured Questions 23 August 2024 2 hours Candidates answer on the Question Paper. READ THESE INSTRUCTIONS FIRST Write your name and class in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 24 printed pages and zero blank page. [Turn over FOR EXAMINER’S USE Q1 / 6 Q2 / 12 Q3 / 5 Q4 / 5 Q5 / 7 Q6 / 11 Q7 / 8 Q8 / 6 Q9 / 20 PAPER 2 / 80 Catholic Junior College JC2 Preliminary Examinations Higher 2

2 DATA speed of light in free space c = 3.00 x 108 m s-1 permeability of free space 0 = 4 x 10-7 H m-1 permittivity of free space 0 = 8.85 x 10-12 F m-1 (1/(36)) x 10-9 F m-1 elementary charge e = 1.60 x 10-19 C the Planck constant h = 6.63 x 10-34 J s unified atomic mass constant u = 1.66 x 10-27 kg rest mass of electron me = 9.11 x 10-31 kg rest mass of proton mP = 1.67 x 10-27 kg molar gas constant R = 8.31 J K-1 mol-1 the Avogadro constant NA = 6.02 x 1023 mol-1 the Boltzmann constant k = 1.38 x 10-23 mol-1 gravitational constant G = 6.67 x 10-11 N m2 kg-2 acceleration of free fall g = 9.81 m s-2

3 [Turn over FORMULAE uniformly accelerated motion s = u t + ½ a t2 v2 = u2 + 2as work done on / by a gas W = p V hydrostatic pressure p = gh gravitational potential  = - Gm r temperature T / K = T / ˚C + 273.15 pressure of an ideal gas p = 1 3 Nm V 〈c2〉 mean translational kinetic energy of an ideal gas molecule E = 3 2 kT displacement of particle in s.h.m. x = x0 sin t velocity of particle in s.h.m. v = v0 cos t = 22 0 xx −  electric current I = Anvq resistors in series R = R1 + R2 + ... resistors in parallel 1/R = 1/R1 + 1/R2 + ... electric potential V = Q 4πεor alternating current / voltage x = x0 sin t magnetic flux density due to a long straight wire B = μoI 2πd magnetic flux density due to a flat circular coil B = μoNI 2r magnetic flux density due to a long solenoid B = μonI radioactive decay x = x0 exp(-t) decay constant λ = 1 2 ln2 t

4 Answer all questions in the spaces provided. 1 A car of mass 1700 kg travels over a curved hump in the road as shown in Fig. 1.1. The radius of curvature of the hump is 45 m. Fig. 1.1 (a) The speed of the car at the top of the hump is 19 m s-1. Determine, for the car at the top of the hump, (i) the magnitude of the centripetal force acting on the car, centripetal force = ………………..……………… N [1] (ii) the magnitude of the normal contact force exerted by the road on the car. normal contact force = ………………………………. N [2] car hump

5 [Turn over (b) Determine the maximum speed vmax that the car can travel at without losing contact with the top of the hump. Explain your working. vmax = ……………………………. m s-1 [3] [Total: 6]

6 2 A long, straight wire W carrying a direct current of 3.0 A flows in the direction as shown in Fig. 2.1. Fig. 2.1 (a) Draw on Fig. 2.1, the pattern of the magnetic field produced by wire W in the regions indicated by the dotted boxes. Use the symbol x to represent magnetic field directed into the page and use the symbol • to represent magnetic field directed out of the page. [3] (b) A similar wire Y is placed parallel to wire W, separated by a distance of 40.0 cm as shown in Fig. 2.2. Initially, there is no current in wire Y. Fig. 2.2 (i) Show that the magnetic flux density at wire Y due to the current in wire W is 1.5  10-6 T. [1] wire W 3.0 A wire W 3.0 A wire Y 40.0 cm

7 [Turn over (ii) A current of 1.0 A is now switched on in wire Y and flows in the opposite direction as the direction of current flow in wire W. Use your answer in (b)(i) to calculate the force per unit length acting on wire Y. force per unit length = …………………….…….. N m-1 [2] (iii) Explain why the force that the two wires exert on each other is repulsive. …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………… [3] (iv) Determine a possible position, other than at infinity, where the resultant magnetic flux density due to the magnetic fields of both wires is zero. position: ………………………………….…………………………. [3] [Total: 12]

8 3 A uniform spherical star has a mass of 6.0 x 10 30 kg. The mass of the star may be assumed to be a point mass at the centre of the star. The star may be considered to be isolated in space. (a) Show that the gravitational field strength at a point 3.0 x 10 9 m from the centre of the spherical star is 44.5 N kg-1. [1] (b) The radius of the star is 1.0 x 109 m. On the axes of Fig. 3.1, sketch a graph to show the variation with distance x from the centre of the star of the gravitational field strength g of the star for values of x from x = 1.0 x 109 m to x = 4.0 x 109 m. [3] (c) State what the area under the graph in Fig. 3.1 represents. ……………………………………………………………………………………………………….. ………………………………………………………………………………………………… [1] [Total: 5] g / N kg-1 x / 109 m Fig. 3.1

9 [Turn over 4 Two parallel plates are in a vacuum. One plate is positively charged and the other plate is earthed. A rectangular conductor of width x is placed in between the plates so that one of its faces is at a distance 0.5x from the positively charged plate and the o pposite face is at 1.5x from the earthed plate as shown in Fig. 4.1. Fig. 4.1 The electric potential difference across the parallel plates is 3.00 V. (a) The variation with distance from P to Q of the electric potential along line PQ is shown in Fig. 4.2. Fig. 4.2 On Fig. 4.2, draw a line to show the variation with distance from R to S of the electric potential along the line RS. [2] + + + + + x 1.5x 0.5x P Q S R conductor positively charged plate electric potential / V distance from positively charged plate 0 0 x 2x 3x 3.00

10 (b) The variation with distance from P to Q of the electric field strength along line PQ is shown in Fig. 4.3. Fig. 4.3 On Fig. 4.3, draw a line to show the variation with distance from R to S of the electric field strength along the line RS. [3] [Total: 5] electric field strength distance from positively charged plate 0 0 x 2x 3x