## Physics Past Paper 10th Class 2010 Karachi Board

## physics 2010

## Time: 30 minutes Max. Marks: 17

## SECTION “A” (COMPULSORY)(M.C.Q.)

**1. Choose the correct answer for each from the given options: (17)**

(i) The Laws of Reflection were first introduced by:

- Yaqoob AI-Kindi
- lbnu-ul-Haitham
- Moosa Khawarzmi
- Al beruni

(ii) In S.I System the unit of mass is:

- Gram
- Pound
- Slug
- Kg

(iii) A 25 N force, acts along the X-axis, its Y-component is:

- 0 N
- 25 N
- 25 N
- None of the above

(iv) The acceleration of a ball thrown vertically upward will, in S.I. system, be;

- 98 m/s^2
- 980 m/s^2
- 9.8 m/s
- 32 m/s^2

(v) A body will be in a state of stable equilibrium if its center of gravity lies

- at the point of suspension
- below the point of suspension
- above the point of suspension,
- none of the above three

(vi) The mass of the earth is:

- 6 * 10 ^24 slugs
- 6 * 10 ^24 grams
- 6 * 10 ^24 N
- 6 * 10 ^24Kg

(vii) The S.I. unit of work is:

- Watt
- Newton
- N-m
- Dyne

(viii) For an ideal machine:

- the output is always greater than the input.
- the output is always equal to the input.
- the output is always less than the input.
- the output is seldom equal to the input

(ix) The pressure of a liquid depends:

- only upon its density.
- only upon its height above the point inside the liquid.
- upon its density as well as height above the point inside the liquid.
- neither upon its density nor height.

(x) The maximum density of pure water is at:

- o0c
- 100 c
- 4°c
- 4°c

(xi) Sound waves cannot travel through:

- water
- a solid
- vacuum
- gases

(xii) A virtual, erect and diminished image is always obtained from a:

- plane mirror
- concave mirror·
- convex mirror
- parabolic mirror

(xiii) The speed of light in a vacuum is

- 3 x 105 Km/hr
- 3 x 108 m/min
- 3 X 108 Km/s
- 3 X 108 m/s

(xiv) If I= 1.5-amps, R = 10 ohms, then V is:

- 15 volts
- 1.5 volts
- 150 volts
- 10 volts

(xv) Shunt converts a galvanometer into:

- a voltmeter
- an ammeter
- a watt meter
- a calorie meter

(xvi) The reflection is obtained from a:

- Transistor
- Capacitor ;
- Resistor
- Semi-conductor Diode

(xvii) Gamma rays are:

- fast-moving neutral particles.
- electromagnetic radiations.
- fast moving positively charged particles.
- fast moving negatively charged particles.

## Physics Past Paper 10th Class 2010 Karachi Board

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

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

2. Define any three branches of Physics.

3. Two forces of 3N and 4N are acting on a body. If the angle between them is 90°, find the magnetic of the resultant vector.

4. If Fx, Fy are the horizontal and vertical components of a vector F, write down the formulae for the magnitude and direction of F. Show Fx, Fy, and F by a diagram

5. A car moving with a uniform acceleration attains a speed of 36km/hr in 2 minutes; find the acceleration of the car

6. Write down three methods of reducing friction

7. Define Linear Momentum. Write down its formula and S.I unit.

8. Define Equilibrium. Write down the conditions of equilibrium and the relate formulae.

9. A stone of 200 gm mass tied to one end of a string of length 50 cm is whirled from the other end in a circle with the constant speed of 2 m/s; find the tension in the string.

10. The length of the handle of a Screw Jack is 42cm and its pitch 1.001m; find its Mechanical Advantage.

11. State Pascal’s Principle. Describe any one of its application.

12. 117.6 J heat is required to raise the temperature of 10gm of silver by 50°C to find the specific heat of silver

13. Define the following: (i) Echo (ii) Ultrasonic wave (iii) beats

14. Define the following: (i) Irregular Reflection (ii) Radius of Curvature (iii) Magnification of a Concave Mirror

15. A convex lens forms a virtual image of an object placed 5cm away from the optical centre at a distance of 10cm. Determine the focal length of the convex lens.

16. Define: (i) Photon (ii) Dispersion of Light (iii) Total Internal Reflection

17. What is the Wave Theory of Light? Write down two phenomena which support this theory.

18. A force of 50N acts on a body. If the moment arm is 0.5m, find the value of the Torque.

19. A 100-watt bulb operates in a 220v circuit; find the current through the bulb.

20. What is an Electromagnet? Illustrate it with a labeled diagram and write down its two uses.

21. Define Reflection. Describe the working of a semiconductor diode as a rectifier.

22. Write down 3 precautions to minimize radiation hazards

## Physics Past Paper 10th Class 2010 Karachi Board

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

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

23.(i) Derive the equation 2a S = v; -V;2

(ii) Write down two characteristic properties of Simple Harmonic Motion.

(iii) The frequency of vibration of a wire is 200 hertz; find its time period.

(iv) Write down four similarities between electrostatic induction and magnetism.

24.(i) Define Evaporation. Write down any four factors on which the rate of evaporation depends.

(ii) Define Kinetic Energy and Potential Energy and write down 2 points of difference between them.

(iii) Draw ray diagrams only to show the nature, position and size of the images formed by a concave mirror when the object is placed:

(a) at the centre of curvature of the mirror.

(b) between the centre of curvature and the principal focus

25(i) What is natural radioactivity? Write down four properties of Alpha rays.

(ii) Define the following:

(a) Refractive Index -(b) Critical Angle

(c) Power of a Lens (d) Magnifying Glass

(iii) What is an electric capacitor? Write down three factors upon which its capacity depends.