d2d entrance exam imp ppt DDCET PHY sics

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1. DDCET Physics LJ Polytechnic

2. DDCET (Diploma to Degree Common Entrance Test ) 2

3. Exam Pattern Total 30 Questions from Physics Topic

4. Study material Basic Physics and Engineering Physics Book (GTU-SEM-1) Applied Physics and Engineering Physics Hand book (LJKU) MCQ Paper (C2D)

5. Table of Content Units and Measurement (20%) Classical Mechanics (20%) Electric Current (20%) Heat and thermometry (20%) Wave motion, optics and acoustics (20%)

6. 1. Units and Measurement (20%) Physical quantities and units. Interconversion of units MKS (SI) to CGS and vice versa. Errors , Estimation of error, relative error, percentage error, propagation of errors. Vernier caliper Micrometer screw gauge.

7. Physical quantities and units. Vector quantity: A vector quantity is a type of physical quantity that has both magnitude and direction. Examples: Displacement, Velocity, Acceleration, Force, and Momentum, etc. Scalar quantity: A scalar quantity is a type of physical quantity that have only magnitude and no specific direction. Examples: Mass, Time, Volume, Speed, Temperature, Distance, etc.

8. Give the SI Unit of Following Quantities Sr No. Quantity Formula Unit 1 Area ( ક્ષેત્રફળ ) L*B m 2 2 Volume ( કદ ) L*B*H m 3 3 Speed Distance / time m/s 4 Velocity ( વેગ ) Displacement / time m/s 5 Acceleration ( પ્રવેગ ) Velocity / time m/s 2 6 Force ( બળ ) Mass * Acceleration Kg.m /s 2 N (newton) 7 Pressure ( દબાણ ) Force / Area N/m 2 Pa (Pascal) 8 Work done ( કાર્ય ) Force * Displacement N.m J (joule) 9 Power Work done / Time N.m /s Watt 10 Density ( ઘનતા ) Mass/Volume kg/m 3 11 Frequency ( આવૃત્તિ ) 1/Time 1/s hz ( heartz )

9. CGS AND MKS(SI) FORCE 1 N = 10 5 dyne Energy 1J = 10 7 erg

10. Vernier caliper Uses LC Construction Zero Error

11. Micro meter screw gauge Uses LC Construction Zero Error

12. Types of Error (a)Absolute error :- it is the difference between true value and the observed value. Average value is considered as true value. -let a1,a2,a3,….an be value of the measurement. -let = a1+a2+a3+……+an n absolute error for each reading :- ! ! ! !  

13. Types of Error (b) Mean absolute error :- it is define as mean of positive values of absolute errors of all the observation (c) Relative error:- it is ratio of average absolute error to the average value . (d) Percentage Error :- relative error measured in percentage is called percentage error.  

14. Significant Number 3401 2100 2100.0 5.00 0.00412 8,000,050,000 4 2 5 3 3 6

15. Question-1 Which of the following is a vector quantity? A. Temperature B. Mass C. Distance D. Force 15 Ans. D. FORCE

16. Question-2 If a measurement has an absolute error of 0.02 cm and the measured value is 2.5cm , what is the relative error? A. 0.01 B. 0.04 C. 0.008 D. 0.08 16 Ans. D = 0.008

17. Question-3 If the length of an object is measured using a Vernier caliper with a least count of 0.01 cm, what is the precision of the measurement? A. 1 mm B. 0.1 mm C. 0.01 mm D. 100 mm 17 Ans. B. 0.1mm

18. Question-4 If a measurement is 5.00 m with a precision of 0.01 m, how many significant figures are in the measurement? A. 1 B. 2 C. 3 D. 4 18 Ans. C. 3

19. 2 . Classical Mechanics (20 %) Linear motion (velocity , acceleration) force , Newton’s laws of motion linear momentum I mpulse of force. Circular motion (angular velocity, angular acceleration) C entripetal and centrifugal force. Work, energy, kinetic energy, potential energy, power .

20. Centrifugal Force AND Centripetal Force : Centrifugal Force: Centrifugal force is a force that acts on an object moving in a circular path, directed outward from the center around which the object is moving . Centripetal Force: Centripetal force is a force that acts on an object moving in a circular path, directed toward the center around which the object is moving.

21. linear momentum and Impulse of force.

22. Question-1 The force that acts on an object moving in a circular path and is directed outward from the centre is called: A. Centrifugal force B. Centripetal force C. Frictional force D. Tension force 22 Ans. A

23. Question-2 In circular motion, which force is responsible for keeping an object moving in a circular path? A. Gravitational force B. Centripetal force C. Centrifugal force D. Frictional force 23 Ans. B

24. Question-3 If a force of 10 N is applied to an object for 5 seconds, what is the impulse of force ? A. 2 N s B. 50 N s C. 2 N D. 50 N 24 Ans. B .

25. Question-4 The equation for kinetic energy (KE) is: KE = (1/2)mv 2 KE = mgh /t KE = Fdt KE = P/t 25 Ans. C. A

26. 3 . Electric Current (20 %) Ohm’s Law Charge Coulomb’s force Electric field, electric potential, electric flux, electric current. Conductance , conductivity • Resistance, resistivity S eries and parallel combination of resistors Capacitance, P arallel plate capacitor, series and parallel combination of capacitors.

27. Coulomb’s force

28. Ohm`s law

29. Resistance and Resistivity

30. Series and Parallel Connection

31. Question-1 A wire has a resistance of 8 Ω . If the current flowing through the wire is 2A, calculate the voltage across the wire. A.4 V B. 16 V C. 4 W D. 16 W 31 Ans. B .

32. Question-2 The property of a material to oppose the flow of electric current is called A.Resistance B. Conductance C. Capacitance D. Susceptance 32 Ans. A.

33. Question-3 The reciprocal of resistance is known as: A. Impedance B. Conductance C. Capacitance D. Susceptance 33 Ans. B.

34. 4 . Heat and thermometry (20%) Modes of heat transfer C onversion of temperature (K , F , C) Heat capacity and specific heat Thermal conductivity, C oefficient of thermal conductivity, L inear thermal expansion.

35. Modes of Heat Transfer

36. Question: What is 30°C in Kelvin ? Solution: The temperature conversion formula from Celsius to Kelvin is, K = C + 273.15 K = 30 + 273.15 K = 303.15

37. Heat capacity and specific heat

38. Question-1 Which of the following is a mode of heat transfer that does not require a medium? A. Conduction B. Convection C. Radiation D. Expansion 38 Ans. C .

39. Question-2 The transfer of heat through the bulk movement of a fluid is known as: A. Conduction B. Convection C. Radiation D. Expansion 39 Ans. B.

40. Question-3 Specific heat is the heat capacity per unit A. Volume B. Mass C. Area D. Temperature 40 Ans. B.

41. Question-4 Which material would generally have the highest thermal conductivity? A. Wood B. Rubber C. Aluminium D. Styrofoam 41 Ans. C .

42. 5.Wave motion, optics and acoustics (20%) Types of waves, Frequency, wavelength, periodic time and their relations. Properties and applications of electromagnetic waves (ordinary light, LASER) S ound waves (ultrasonic wave, audible wave) Amplitude, intensity, phase and wave equations. Reverberation, Reverberation time, Sabine’s formula, echo, absorption coefficient. Reflection, refraction, Snell’s law, absolute refractive index, relative refractive index T otal internal reflection, critical angle, optical fiber (construction, properties and applications).

43. Types of Wave

44. Equation

45. Snell`s Law

46. Question-1 The distance between two successive points in a wave in the same phase is called : A.Wavelength B. Frequency C. Amplitude D. Periodic time 46 Ans. A.

47. Question-2 If the frequency of a wave is 50 Hz, what is its periodic time? A. 0.02 s B. 0.04 s C. 0.5 s D. 2 s 47 Ans. A.

48. Question-3 The change in direction of a wave when it crosses the boundary between two different media is called: A. Reflection B. Refraction C. Diffraction D. Absorption 48 Ans. B.

49. Question-4 According to Snell's Law, the angle of incidence is related to the angle of refraction by: n1 sin( θ1) = n2 sin( θ2) n1 cos ( θ1) = n2 cos ( θ2) n1 cot( θ1) = n2 cot( θ2) n1 tan( θ1) = n2 tan( θ2) 49 Ans. A.

50. Thanks