# Bise Karachi 10th Physics Solved Guess Paper

**Physics Solved Guess Paper **

**SECTION “A” Q.1 (a) Derive the equation 2aS = Vf2 – Vi2. (05) (b) Write the contribution of each of the following in the field of Physics. (04) i. Al-Beruni ii. Yaqoob Al-Kandi (c) A mass of 10 kg at the end of a string is being whirled in a circle of radius 5 cm with a speed of 4 m/s. What will be the centripetal force? (03) Data Mass of Body = M = 10 kg Radius of Circle = r = 5m Velocity of object = V = 4 m/s Centripetal force = Fc = ? Solution .. Fc = mV2/r –> Fc = 10 x (4)2 / 5 –> Fc = 10 x 16 / 5 –> Fc = 2 x 16 –> Fc = 32 N Centripetal Force = 32N Ans. (d) One milliampere = 10-3 (01) Q.2 (a) State Pascal” s Law and explain the working of a hydraulic brake system with the help of a diagram. (05) (b) Write two points of difference between the following (04) i. Scalar and Vector Quantities ii. ” g” and ” G” (c) A car moving with a velocity of 36 km/hr is brought to ret in 5 seconds, find its deceleration. (03) Data Initial Velocity of car = Vi = 36 km/hr 36 x 1000 / 60 x 60 = 10 m/s Find Velocity of car = Vf = O m/s Time = t = 5 seconds Decleration = a = ? Solution .. Vf – Vi + at –> a = Vf – Vi / t –> a = 0 – 10 / 5 –> a = -10 / 5 –> a = -2 m/s2 Decleration of Car = 2 m/s2 Ans. (d) The point at which the whole weight of a body appears to act is called center of gravity (01) Q.3 (a) Define Newton” s Law of Gravitation and find the equation for the mass of earth with the help of F = G m1m2 / r2 (5) (b) A 100 kg car is accelerated from rest at 4 m/s2 for 10 seconds calculate the work done. (04) Data Mass of Car = m = 100 kg Acceleration of car = a = 4 m/s2 Time = t = 10 seconds Force = F = ? Initial velocity of car = Vi = 0 m/s Final velocity of car = Vf = ? Distance covered = S = ? Word done = w = ? Solution .. F = ma –> F = 100 x 4 –> F = 400N .. Vf = Vi + at –> Vf = 0 + 4 x 10 –> Vf = 40 m /s .. 2aS = Vf2 – Vi2 –> S = Vf2 – Vi2 / 2a –> S = (40)2 – o2 / 2 x 4 –> S = 1600 / 8 –> S = 200 m –> W = 400 x 200 –> W = 80,000J Word done = 8 x 104 J Ans (c) State the following Laws (03) i. Hooke” s Law ii. Law of Inertia iii. Law of Conservation of Energy (d) Steam produces more severe burns on the body than the hot water. (Give the Scientific Reason) (01) Q.4 (a) Draw a labelled diagram of a refrigerator and describe the working of its main parts. (05) (b) Write two points of difference between the following. (04) i. Distance and Displacement ii. Kinetic Energy and Potential Energy (c) Define the following terms (03) i. Elasticity ii. Newton (unit) iii. Force (d) The fundamental unit of length is S.I. System is metre. Q.5 (a) Define Evaporation and write any four factors on which the rate of evaporation depends. (05) (b) What is the kinetic energy of a 200 kg car which is travelling with a velocity of 36 km/hr? (04) Data Mass of Car = m = 200 kg Velocity of car = V = 36 km / hr = 36 x 1000 / 60 x 60 = 10 m/s Kinetic Energy = K.E = ? Solution .. K.E = 1/2 mV2 –> K.E = 1/2 x 200 x (16)2 –> K.E = 1/2 x 200 x 100 ==> K.E = 10,000J ANS (c) Write three methods of reducing friction. ( 03) (d) Mechanical advantage of a screwjack (M.A) = 2nd / h SECTION “B” Q.6 (a) With the help of a labelled diagram, explain the working of an Electric Bell. (04) (b) A body is kept at a distance of 10 cm form a concave mirror. The radius of curvature of the mirror is 10 cm, find the position and nature of the image. (04) Data Distance of object = P = 10 cm Radius of curvature = R = 10 Focal length = f = ? Position of image = q = ? Nature of image = ? Solution .. f = R/2 –> f = 10 /2 –> f = 5 cm .. 1/f = 1/p + 1/q –> 1/q = 1/f – 1/p –> 1/q = 1/5 – 1/10 –> 1/q = 2-1/10 –> 1/q = 1/10 –> q = 10 cm Position of Image = 10 cm Nature of Image = Real, equal in size ANS (c) Define the following (03) i. Focal length ii. Farad iii. Critical angle (d) The device which collects the charge is called Capacitor (01) Q.7 (a) Explain the working of a compound microscope with the help of a ray diagram. (04) (b) Write two points of difference between the following. (04) i. Direct Current and Alternating Current ii. Real Image and Virtual Image (c) Define Coulumb” s Law and derive its formula. (03) (d) The substance used as a medium between the two plates of a capacitor is called insulator (01) Q.8 (a) With the help of a ray diagram show the nature size and position of the image formed in a concave mirror when (04) i. the object is placed beyond ” C” ii. the object is placed between ” C” and ” F” (b) Find the current passing through the heater which has a resistance of 20 ohms and a potential difference of 220 V is supplied to it. Data Current Passing = I = ? Resistance = P = 20 Potential Difference = V = 220 vatts Solution .. V = IR –> I = V/R –> I = 220/20 –> I = 11A Current Passing 11 ampere ANS (c) Define Photon & write of its characteristics (03) (d) It a low resistance is connected parallel to a galvanometer it is converted into Ammeter (01) SECTION “C” Q.9 (a) Define Loudness of sound. Give any three factors on which it depends. (04) (b) Write two points of difference between the following (04) i. Alpha Rays and Beta Rays ii. Fission Reaction and Fusion Reaction (c) Write three advantage of a Transistor (03) (d) The number of protons in a nucleus is called Mass Number (01) Q.10 (a) Define Radio-Isotopes and write any three uses of radio-isotopes in Industry. (04) (b) When a sound wave of frequency 200Hz and wave length 3m passes through a medium calculate the velocity of the wave in that medium. Data Wave Requency = f = 200Hz Wave length = h = 3m velocity of wave = V = ? Solution .. V = fh –> V = 200 3 –> V = 600 m/s Velocity of the Wave = 600 ms ANS (c) Define the following (03) i. Time Period ii. Amplitude iii. Doping (d) The sound of explosion on the sun is no theard on the earth (Give the scientific reason) (01)**