ISC Physics 2018 Specimen Paper with Answers
All 40 questions of the ISC Physics 2018 Specimen Paper, in printed order. Open a question to read it in full and see its answer.
- Q1(A)(i) Ohm’s law in vector form is: 1 mark · MCQ
- Q1(A)(ii) Current flowing through a long solenoid is varied. Then, magnetic flux density of the magnetic field inside it varies: 1 mark · MCQ
- Q1(A)(iii) A convex lens, made of glass, is immersed in water. As a result, its focal length will: 1 mark · MCQ
- Q1(A)(iv) de Broglie wavelength of a moving particle is $\lambda$. Its momentum is given by: 1 mark · MCQ
- Q1(A)(v) Half Life of a certain radioactive substance is $69\cdot3$ days. Its disintegration constant is: 1 mark · MCQ
- Q1(B)(i) How will the sensitivity of a potentiometer change with increase in current flowing through its wire? 1 mark · Short answer
- Q1(B)(ii) Which of the two; an ammeter or a voltmeter, has a greater resistance? 1 mark · Short answer
- Q1(B)(iii) Why is soft iron preferred to steel in making the core of a transformer? 1 mark · Short answer
- Q1(B)(iv) When would a moving charged particle travel undeviated in a uniform magnetic field? 1 mark · Short answer
- Q1(B)(v) Complete the ray diagram shown in Figure 1, given that the critical angle for air-glass pair is $i_c = 42^\circ$. 1 mark · Drawing
- Q1(B)(vi) State the Law of Malus. 1 mark · Short answer
- Q1(B)(vii) Name any one material used as a moderator in a nuclear reactor. 1 mark · One word
- Q2 Define drift velocity and relaxation time, with reference to the free electron theory of conductors. 2 marks · Short answer
- Q3 A long straight wire is bent as shown in Figure 2 below. Find the resultant magnetic field ‘$B$’ at the centre C of the circular… 2 marks · Numerical
- Q4 Explain the meaning of the statement: “Angle of dip at a certain place on earth is $60^\circ$.” If the horizontal component of… 2 marks · Numerical
- Q5(a) Briefly explain the following terms: Curie temperature Self-induction 2 marks · Short answer
- Q5(b) Name any two types of energy losses in a transformer. State how any one of them can be minimized. 2 marks · Short answer
- Q6 What is displacement current? Which electromagnetic radiation is used to study the crystal structure? 2 marks · Short answer
- Q7 A thin convex lens of focal length $20\text{ cm}$ is kept in contact with a thin concave lens of focal length $15\text{ cm}$… 2 marks · Numerical
- Q8 What is meant by dispersive power? Write an expression of dispersive power in terms of refractive indices. 2 marks · Short answer
- Q9(a) For each of the following, state one phenomenon in which: particles behave like waves. waves behave like particles. 2 marks · Short answer
- Q9(b) Plot a labelled graph of maximum kinetic energy of photo electrons versus frequency of incident radiation. State how you will… 2 marks · Drawing
- Q10 Draw energy level diagram for Hydrogen atom showing at least four lowest energy levels. Show the transitions responsible for… 2 marks · Drawing
- Q11 What is meant by ‘binding energy per nucleon’ of a nucleus? State its physical significance. 2 marks · Short answer
- Q12 Name essential components of a communication system. Draw its block diagram. 2 marks · Short answer
- Q13 Using Gauss’ theorem, obtain an expression for intensity of electric field ‘$E$’ at a point, which is at a distance ‘$r$’ (… 3 marks · Derivation
- Q14(a) Obtain an expression for electric potential ‘$V$’ due to a point charge ‘$Q$’ at a distance $r$. 3 marks · Derivation
- Q14(b) A parallel plate capacitor is charged by a battery; which is then disconnected. A dielectric slab is now introduced between the… 3 marks · Short answer
- Q15 Using Kirchhoff’s laws of electrical networks, calculate the currents $I_1$, $I_2$ and $I_3$ in the circuit shown below (Figure… 3 marks · Numerical
- Q16(a) Obtain an expression for refraction at a single convex spherical surface separating the two media having refractive indices… 3 marks · Derivation
- Q16(b) Derive $R = 2f$ for a spherical mirror, where the symbols have their usual meaning. 3 marks · Derivation
- Q17 When a ray of ordinary light is incident on the surface of separation of two media at polarizing angle, show with the help of a… 3 marks · Short answer
- Q18 For radioactive disintegration of a radioactive substance, show that $N = N_0 e^{-\lambda t}$\nwhere the terms have their usual… 3 marks · Derivation
- Q19 With reference to a semiconductor diode, define the terms ‘depletion region’ and ‘potential barrier’. How will the width of… 3 marks · Short answer
- Q20(a) An $8\text{ H}$ inductor, a $2\ \mu\text{F}$ capacitor and a $100\ \Omega$ resistor are connected in series to an A.C. supply of… 5 marks · Numerical
- Q20(b) An A.C. generator generating an emf ‘$E$’ given by $E = 311 \sin(100\pi t)$ is connected to a $44\ \Omega$ resistor. Calculate… 5 marks · Numerical
- Q21(a) Draw a labelled ray diagram of an image formed by a compound microscope with final image formed at the least distance of distinct… 5 marks · Derivation
- Q21(b) Draw a neat and labelled diagram of an experimental setup of Young’s double slit experiment to study the interference of light… 5 marks · Derivation
- Q22(a) For a transistor in a common emitter mode, draw labelled graph to show: (1) Input characteristic curve. (2) Output characteristic… 5 marks · Short answer
- Q22(b) Show how you will obtain an AND gate using only NOR gates. Draw the truth table for this arrangement of gates. For a common… 5 marks · Short answer