RI Y6 Remedial E-field Assignment

Raffles Institution Year 5-6 Physics Department 1 2025 Year 6 H2 Physics Remedial Chapter 13: Electric Fields 2 0 118.85 10 F m ε −−× = , 191.60 1 0Ce −× = , 3110 k 11g9. em −= × , 2710 k 67g1. pm −= × 1 Two ions A and B are separated by a distance of 5.00 mm in a vacuum, as shown in Fig. 1.1. A has a charge of −4.80 × 10–19 C and B has a charge of +1.60 × 10 –19 C. Point X is located 3.00 mm from A and 4.00 mm from B. Fig. 1.1 (a) Calculate the magnitude of the resultant electric field strength at X. [2] (b) Calculate the electric potential at X. [2] 2 (a) Define electric field strength at a point in an electric field. [1] (b) Fig. 2.1 shows two isolated point charges X and Y. X carries a charge of +3.2 × 10−10 C, while Y carries a charge of −6.2 × 10−10 C. The two charges are 0.20 cm apart. Sketch on Fig. 2.1, the resultant electric field lines due to the two charges. Fig. 2.1 [3] (c) A test charge T of +1.2 × 10-10 C is placed 0.10 cm from X such that XTY forms a right angle as shown in Fig. 2.2. Fig. 2.2 5.00 mm 3.00 mm 4.00 mm A B X X Y +3.2 × 10−10 C +1.2 × 10−10 C X Y −6.2 × 10−10 C T 0.20 cm 0.10 cm

Raffles Institution Year 5-6 Physics Department 2 (i) Calculate the magnitude of the net force, F, acting on T. [3] (ii) Indicate its general direction in Fig. 2.2 (Exact calculation for the direction is not required.) [1] [NYJC/Prelim 2014/P3/3] 3 (a) Two small charged metal spheres A and B are situated in a vacuum. The distance between the centres of the spheres is 12.0 cm, as shown in Fig. 3.1. Fig 3.1 (not to scale) The charge on each sphere may be assumed to be a point charge at the centre of the sphere. Point P is a movable point that lies on the line joining the centres of the spheres and is distance x from the centre of sphere A. The variation with distance x from the centre of sphere A of the electric field strength E at point P is shown in Fig. 3.2. Fig 3.2 12.0 cm P sphere A sphere B

Raffles Institution Year 5-6 Physics Department 3 (i) Define electric field strength. [1] (ii) State the evidence provided by Fig. 2.2 for the statements that 1. the spheres are conductors, [1] 2. the charges on the spheres are both positive. [2] (iii) An α-particle is placed at rest at x = 4.0 cm on the line joining the centres of the spheres. Describe what will happen to the α-particle. [2] [AJC/Prelims 2014/P3/9(a)] 4 (a) Two vertical parallel metal plates X and Y are situated 3.20 cm apart in a vacuum, as shown in Fig. 4.1. Plate X is maintained at a potential of −600 V and plate Y is earthed. Fig. 4.1 An electron is initially at rest close to the negative plate and in the electric fiel