## Physics Past Paper 10th Class 2011 Karachi Board

## physics 2011

## Time: 30 minutes Max. Marks: 17

## SECTION “A” (COMPULSORY)(M.C.Q.)

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

(i) Amplification can be obtained by:

- (a) Radar
- (b) Transistor
- (c) P.N.Junction
- (d) Capacitor

(ii) If V=10 m/s, t=5 sec, S will be:

- 15 m
- 5 m
- 2 m
- 50 m

(iii) The elements having atomic Number greater than 82 are called:

- Semiconductor
- Conductor
- Insulator
- Radioactive elements

(iv) The substance placed between the conductor plates of the capacitor is called:

- Dielectric
- Capacitor
- Insulator
- Resistance

(v) In S.1.Unit value of G is:

- 6.67 X 1011 Nm2/Kg2
- 6.67 X 10·11 Nm2/K~2
- 6.76 x 1011 Nm2/Kg2
- 6.76×10″11 Nm2/Kg

(vi) Maximum beat frequency that human ear can detect is:

- 6
- 7
- 5
- 10

(vii)Unit of light intensity is:

- N/m^2
- Volt
- Candela
- Joule

(viii) Which of the following is same as Kg.m/s2

- joule
- Newton
- Pascal
- Watt

(ix) Loudness of sound depends upon:

- Area of vibration
- Amplitude
- Frequency
- All of them

(x) Rate of motion in specific direction is called:

- Speed
- Velocity
- Acceleration
- Power

(xi)Equivalent weight of 10 kg is:

- 98 N
- 980 N
- 100 N
- 196 N

(xii) Which of the following never gives a real image:

- Plane mirror
- Concave mirror
- Convex mirror
- Human eye

(xiii) One micrometer is equivalent to:

- 10·3m
- 10·6m
- 10·9m
- 10·12m

(xiv) Refractive index of water is:

- 1.5
- 1
- 2.4
- 1.33

(xv) Human eye is similar to:

- Microscope
- Telescope
- Camera
- Periscope

(xvi)Kitab-AI-Manazir is written by:

- lbn-al-Haitham
- Yaqoob-al-Kindi
- AI-Beruni
- Moosa Kawarzmi

(xvii) Acceleration of 1 kg ball for downward motion is:

- 9.8 m/s2
- 9.8 m/s2
- 1 m/s2
- 98 m/s2

## Physics Past Paper 10th Class 2011 Karachi Board

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

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

2. Define physics and write down only the names of four branches.

3. A body weighing 25 N is placed on a wooden plank. How much force is required to set it in motion if the coefficient of friction between the plank and the body is 0.4?

4. Define Work and write down its two formulas

5. Define the following: (i) Limiting frictions (ii) Inertia (iii) Power

6. Define machine and write down the names of four simple machines.

7. What is Transistor? Write its two advantages.

8. Draw a labeled diagram of an electric bell.

9. Write down three differences between Mass and Weight.

10. A body of 20 Kg is moving at a speed of 15 miles. Find its momentum.

11. How much heat is required to raise the temperature of 100kg of Iron through 10oC? (Specific hear of iron is 499.8 J/lg°C)

12. Define the following: (i) Dispersion of Light (ii) Magnification (iii) Focal length of the Concave mirror

13. Draw the ray diagram for the formation of an image in a plane mirror.

14. Calculate the amount of current passing through an electric heater if it takes 1800C of charge to heat in 3 min.

15. Prove that V = f lambda

16. Find the Focal length of a concave lens if P = 5cm, q = 10cm and the image formed is virtual.

17. A stone is dropped. from a tower. It reaches the ground in 5 seconds. Calculate the height of the tower.

18. Define resolution of vector and write down two formulae of rectangular components.

19. Describe Quantum theory of light.

20. A Sitar string vibrates at 400Hz. What is the time period of this vibration?

21. Define the following: (i) Half-life of radioactive elements. (ii) Doping (iii) Magnetic field

22. In a nuclear reaction, 9 x 1010J of energy is released due to the conversion of mass into energy. How much mass has been converted into energy? (Speed of light is 3x 108m/s)

## Physics Past Paper 10th Class 2011 Karachi Board

## SECTION ‘C’ (DETAILED-ANSWER QUESTIONS)

** NOTE: Attempt 2 questions from this section. (26)**

23.(a) Derive the equation S = V;t + ½ at2

(b) Draw the ray diagram of a compound Microscope and write its working

(c) Define Radioisotopes and state its one use in agriculture and two uses in medicine.

24.(a) State Boyle’s law, Charles’ Law, and Pressure Law. Derive PV = nRT.

(b) Draw Ray diagram for an image formed by the Concave mirror and write its characteristics.

(c) What is Radar? Write its three uses.

25. (a) Define Fission reaction. Write down its equation and draw the diagram for the chain reaction.

(b)Define the following:

(i) Ampere (b) Volt (c) Farad (d) ohm

(c)State the following laws/principles:

(i) Hooke’s Law (ii) Pascal’sPrinciple

(iii) Newton’s Second Law of Motion (iv) Snell’s Law