TMA2/PHY192

My TMA Home TMA Results My Pending TMA Quick Help TMA Quiz Questions TMA: TMA2/PHY192   SCORE=10.00 PHY192 - Physics Practical II Mr. Ibanga Efiong (eibanga@noun.edu.ng ) 1 Diopter is the unit of linear magnification power of lens inverse of object distance from lens inverse of image distance from lens 2 In an experiment involving the convex lens, , which of the following is NOT correct? images must always be sharply focused the tip of object pin must be at the same height as the centre of lens images obtained must always be magnified parallax error must be avoided 3 Describe the image of a candle positioned 20cm in front of a concave mirror of focal length 30cm virtual, inverted, 12cm behind mirror and magnified 3 times real, inverted, 12cm in front of mirror and diminished 3 times virtual, erect, 60cm behind mirror and magnified 3 time  real, erect, 60cm in front of mirror and diminished 3 times 4 Which of the following is correct about tracing ray digrams with curved mirrors rays incident at the centre of the mirror are reflected through the centre of curvature rays passing through the centre of curvature are reflected through the pricipal focus rays passing through the pricipal focus are reflected on themselves rays parallel and close to the principal axis are reflected through the pricipal focus 5 Convex mirrors are mostly used as magnifying glasses driving mirrors dentist mirrors artist mirrors 6 In an experiment involving a spherical mirror, 1/v was plotted on the vertical axis and 1/u on the horizontal axis. What is the linear magnification? slope of the graph inverse of the the slope of the graph intercept on the vertical axis intercept on the horizontal axis 7 Which of the following is NOT true of experiments involving curved mirrors? image distance is negative for for real image object distance is positive image distance is negative for virtual image focal length is negative for convex mirrors 8 The null condition in potentiometer experiment shows that the potential difference under test is zero current is varying in the circuit  current is increasing in the circuit potential differences are balanced 9 The potentiometer wire plays equivalent role of which of these devices in a circuit? rheostat thermostat galvanometer ammeter 10 The advantage of potentiometer over voltmeter in measurements of emf is that the potentiometer wire is assumed to be uniform it does not draw current from the circuit under test the temperature of the wire must remain constant faults may arise due to breaks or wrong connections in the circuit 11 Which of these is not a useful precaution in an electrical experiment? key should be removed between readings to avoid battery run-down jockeys should be dragged on resistance wires the connections in the circuit should be tight readings should be recorded as soon as they are obtained 12 Which of the following is not true about a rheostat? It is a constant current instrument It is a variable resistor with moving contact It is used for varying the current in a circuit It is used for varying the resistance in a circuit 13 In an experiment, potential difference is plotted on the ordinate (vertical axis) and current on the abscissa(horizontal axis). The slope of the graph represents potential difference current remains constant resistance resistivity 14 In the circuit diagram shown, the device marked X is a ----------------- Click here to see exhibit rheostat voltmeter jockey galvanometer 15 The null condition in potentiometer experiment shows that the potential difference under test is zero current is varying in the circuit potential differences are varying in the circuit potential difference are balanced 16 A ray incident on a glass prism undergoes minimum deviation when the incident angle is equal to the angle of refraction refraction angle equals 90o incident angle equals 90o incident angle is equal to the angle of emergency 17 The advantage of potentiometer over voltmetr in measurements of emf is that the potentiometer wire is assumed to be uniform it does not draw current from the circuit under test the temperatue of the wire must remain constant faults may arise due to breaks or wrong connections in the circuit 18 Which of these is not a useful precaution in an electrical experiment? key should be removed between readings to avoid battery run-down jockeys should be dragged on resistance wires the connections in the circuit should be tight readings should be recorded as soon as they are obtained 19 Which of the following is NOT true about a rheostat? It is a constant current instrument It is a resistor with moving contact It is used for varying the current in a circuit It is used for varying the resistance in a circuit 20 For a metallic conductor, Ohm's law holds provided potential difference varies current remains constant temperature remains constant potential difference remains constant