## Physics Past Paper 10th Class 2012 Karachi Board

# PHYSICS 2012

## Time: 30 minutes Max. Marks: 17

## SECTION ‘A’ MULTIPLE CHOICE QUESTION

** 1. Choose the correct answer for each from the given options:**

(i) The refractive index of Ruby is.

- 1.51
- 1.52
- 1.53
- 1.54

(ii) The least distance of vision for a normal Eye is:

- 20 cm
- 25 cm
- 30 cm
- 35 cm

(iii) The speed of Light in water is:

- 2.25 x 108 m/s
- 2.26 x 108 m/s
- 2 x 108 m/s
- 3 x 108 m/s

(iv) One Nano metre is equal to

- 10·3m
- 10·5m
- 10″9m
- 10·12m

(v) Evaporation takes place at:

- 0°C
- 100°C
- 100°C
- All temperature

(vi) The focal length of +2 diopter convex lens is:

- 10 cm,
- .25 cm
- 50 cm
- 75 cm

(vii) The rate of the flow of charge in a conductor is called:

- Current
- Volt
- Farad
- Coulomb

(viii) The relation between magnetic field and electric current was discovered by:

- Newton
- Oersted
- Faraday
- Fleming

(ix) When two forces Fx = SN and Fy = 6N are acting on a body, the angle between them will be;

- Less than 30°
- 30°
- 45°
- 60°

(x) The time period of Second’s Pendulum is:

- 1 Second
- 2 Seconds
- 3 Seconds
- 4 Seconds

(xi) If mass of a body is 10 kg, its weight will be:

- 9.8 gm
- 98 N
- 0.98 N
- 0.98 kg

(xii) The Lightest particle in an atom is.

- Neutron
- Proton
- Alpha Particle
- Electron

(xiii) Joule per Coulomb is called:

- ampere
- ohm
- volt
- watt

(xiv) The wave produced by a vibrating body in air is:

- Transverse wave
- Longitudinal wave
- Electromagnetic wave
- Stationary wave

(xv) If q = 6 cm and p = 2 cm , magnifying power of lens will increase:

- 2 times
- 3 times
- 4 times
- 5 times

(xvi) The speed of sound at N.T.P (Normal temperature and pressure) is:

- 336 m/s
- 340 m/s
- 342 m/s
- 350 m/s

(xvii) It is not a simple machine:

- Pair of scissors
- Pair of forceps
- Door
- Bicycle

## Physics Past Paper 10th Class 2012 Karachi Board

## SECTION “B” (SHORT-ANSWER QUESTIONS)

** Note: Answer 14 questions from this section.**

2. Define scalar and vector quantities with two examples of each.

3. Define Equilibrium. Write the Rames of three states of equilibrium. Give one example of each.

4. With the help of trigonometric ratios, find the magnitude of horizontal and vertical components of a vector.

5. A car is moving on a straight road at a speed of 5 m/s. It is accelerated at 3 m/s^2 Calculate its velocity after 4 seconds.

6. Write down three contributions of AI-Beruni in the field of science.

7. State Pascal’s principle & write its three uses in daily life

8. Define the following Laws: · (i) Boyle’s Law (ii) Law of conversation of Momentum (iii) Newton’s Third Law of Motion

9. How much amount of heat is required to raise the temperature of 100 gm of ,water from 20°C to 80°C. (Specific heat of water is 4200 Joules)

10. What is Newton Corpuscular Theory of light. Write down two phenomena which supp~rt this Theory.

11. A force of 588 N acts on a box to move it at a distance of· 4m in 40 Seconds. Calculate the power.

12. Define the following: (i) Alternating Current (A.C) (ii) Electric Field (iii) Electrostatic Induction

13. Write three uses of the concave mirror.

14. Write three differences between A – rays and B – rays.

15. Derive the relation w = I^2 Rt

16. What is. a Transistor? Describe two types of a transistor with the help of diagrams.

17. Find the resistance of a bulb, if 0.6 A current is passing through the bulb and the potential difference across the bulb is 90 Volt.

18. Define the coefficient of Linear Expansion and coefficient of Volumetric Expansion. Write the relation between them.

19. The radius of curvature of a concave mirror is 20 cm. where should an object be placed so as to get its real image magnified twice?

20. Write down three characteristics of the image formed by a plane minor.

21. A force of 100 N acts at an angle of 60° with the horizontal. Find its horizontal and vertical components, where Cos60° = 0.5 and Sin 60° = 0.866

22. Write down any three characteristics of resistances ·connected in parallel.

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## Physics Past Paper 10th Class 2012 Karachi Board

## SECTION ‘C’ (DETAILED – ANSWER QUESTION)

** NOTE: Attempt 2 questions from this section.**

23.(a) Define potential energy and kinetic energy and derive the equation K.E = ½ mv^2 (05)

(b) Define the capacity of a capacitor. Write down three factors upon which capacity of a capacitor depends. (04)

(c) Define the following: (04)

(i) Proton (ii) Echo (iii) Nuclear Reactor (iv) Doping

24.(a) Define Coulomb’s Law. Derive the equation: F=K q1 q2/r^2. (05)

(b) Define Radio Isotopes. Write the uses of following Radio Isotopes

(i) Co-60 (ii) 1-131 (iii) P-32 (04)

(c) Define the loudness of. sound. Write three factors on which the loudness of a sound depends. (04)

25.(a) Derive equation 2aS = vf^2 – vi^2 (05)

(b) Draw a neat labeled ray diagram of the simple microscope. Write down the characteristics of the image formed by it and the formula of its magnifying power. (04)

(c) Define the following: (04)

(i) Simple Harmonic Motion (ii) Frequency (iii) Time Period (iv) Pitch