9th Class Physics Past Paper 2021
Note: Physics 1st Time Paper of 9th Class.
Group-I (Subjective) 40 Marks
Part– I
Q.2 Write short answers to any FIVE (5) questions:
(i) Define base units and derived units.
(ii) Define positive and negative zero error of vernier calipers.
(iii) Define prefixes and give two examples.
(iv) Define velocity and write its formula.
(v) Convert 50 km/h-1 to m/s-1.
(vi) Define rest and motion.
(vii) Why is rolling friction smaller than sliding friction?
(viii) Define centripetal acceleration and write its formula.
Q.3 Write short answers to any FIVE (5) questions:
(i) Differentiate between like and unlike parallel forces.
(ii) Define torque and write its mathematical equation.
(iii) What do you know about the center of gravity?
(iv) What is meant by “G“? What is its value?
(v) Define artificial satellite.
(vi) Define orbital velocity and write its formula.
(vii) Define power and write its formula.
(viii) What is meant by the efficiency of a system?
Q.4 Write short answers to any FIVE (5) questions:
(i) Why strain has no unit? Give reason.
(ii) Define elastic limit.
(iii) Write down the formula for pressure and strain.
(iv) Define latent heat of fusion.
(v) What is meant by internal energy?
(vi) What is the effect of temperature on evaporation?
(vii) How does heat reach us from the sun?
(viii) Why does the land breeze blow at night?
PART-II
Note: Attempt any TWO questions.
Q.5
(a) State Newton’s first law of motion and explain with the help of two examples.
(b) A train starts from rest with an acceleration of 0.5 m/s-2. Find its speed in Kmh-1 when it has moved through 100 m.
Q.6
(a) Define potential energy, give an example, and derive its equation.
(b) Find the magnitude and direction of the force, if its X-component is 12 N and Y-component is 5 N.
Q.7
(a) State Pascal’s law and explain the hydraulic press.
(b) Calculate the increase in the length of an aluminum bar 2 m long when heated from 0°C to 20°C. The thermal coefficient of linear expansion of aluminum is 25 × 10⁻⁶ K-1.