9th Class Physics Past Paper 2018
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 Plasma Physics and Geophysics.
(ii) What do you mean by scientific notation? Give an example.
(iii) Change 15 years of age into seconds.
(iv) Define translatory motion and give an example.
(v) Define acceleration and write its unit.
(vi) State Newton’s first law of motion.
(vii) Why is rolling friction less than sliding friction?
(viii) When a gun is fired, why does it recoil?
Q.3 Write short answers to any Five (5) questions:
(i) What is the second condition of equilibrium? Write its formula.
(ii) Define resolution of forces.
(iii) State Newton’s law of gravitation.
(iv) Why can we not feel the gravitational force around us?
(v) Define field force and gravitational field strength.
(vi) Define power and write its SI unit.
(vii) A body of mass 50 kg is raised to a height of 3 m. What is its potential energy? (g = 10 m/s²)
(viii) What is meant by nuclear energy?
Q.4 Write short answers to any Five (5) questions:
(i) Define pressure and write its SI unit.
(ii) The mass of 200 cm³ of stone is 500 g. Find its density.
(iii) What is a barometer? Explain it.
(iv) Convert 100°F into the Celsius scale.
(v) Define specific heat and write its mathematical formula.
(vi) What is meant by convection currents in air?
(vii) Define radiation.
(viii) Write two names of expert thermal climbers.
PART-II
Note: Attempt any TWO questions.
Q.5
(a) Derive the second equation of motion with the help of the speed-time graph.
(b) How much centripetal force is needed to make a body of mass 0.5 kg move in a circle of radius 50 cm with a speed of 3 m/s-1?
Q.6
(a) Write the four uses of solar energy.
(b) Find the perpendicular components of a force of 50 N making an angle of 30° with the x-axis.
Q.7
(a) Define linear thermal expansion in solids. Derive its formula:
L = L₀(1 + αΔT)
(b) The head of a pin is a square with a side of 10 mm. Find the pressure on it due to a force of 20 N.