1. A constant voltage is applied between the two ends of a uniform metallic wire. Some heat is developed in it. The heat developed is doubled if ? the length of the wire is doubled. the radius of the wire is doubled. both the length and the radius of the wire are halved. both the length and the radius of the wire are doubled. Answer: both the length and the radius of the wire are doubled. Explanation: A constant voltage is applied between the two ends of a uniform metallic wire. Some heat is developed in it. The heat developed is doubled if both the length and the radius of the wire are doubled. View Answer Discuss in Forum Report Question

 2. The relaxation time in conductors ? decreases with the increases of temperature it does not depends on temperature increases with the increases of temperature all of sudden changes at 400 K Answer: decreases with the increases of temperature Explanation: The relaxation time in conductors decreases with the increases of temperature View Answer Discuss in Forum Report Question

 3. The example of non-ohmic resistance is ? carbon resistor diode copper wire filament lamp Answer: diode Explanation: The example of non-ohmic resistance is diode. View Answer Discuss in Forum Report Question

 4. To draw a maximum current from a combination of cells, how should the cells be grouped ? Series Mixed grouping Parallel epends upon the relative values of internal and external resistances Answer: Parallel Explanation: To draw a maximum current from a combination of cells, Parallel combination should the cells be grouped View Answer Discuss in Forum Report Question

 5. For measuring voltage of any circuit, potentiometer is preferred to voltmeter because ? range of the voltmeter is not as wide as that of the potentiometer. the potentiometer almost draws no current during measurement. calibration in the voltmeter is sometimes wrong. the potentiometer is cheap and easy to handle. Answer: the potentiometer almost draws no current during measurement. Explanation: For measuring voltage of any circuit, potentiometer is preferred to voltmeter because the potentiometer almost draws no current during measurement. View Answer Discuss in Forum Report Question

 6. The current which is assumed to be flowing in a circuit from positive terminal to negative, is called ? conventional current alternating current pulsating current direct current Answer: conventional current Explanation: The current which is assumed to be flowing in a circuit from positive terminal to negative, is called conventional current View Answer Discuss in Forum Report Question

 7. When there is an electric current through a conducting wire along its length, then an electric field must exist ? inside the wire but normal to it. outside the wire but parallel to it. outside the wire but normal to it. inside the wire but parallel to it. Answer: inside the wire but parallel to it. Explanation: Electric field parallel to wire inside creates potential difference and electrostatic force on electrons. View Answer Discuss in Forum Report Question

 8. Which of the following is wrong? Resistivity of a conductor is ? less than resistivity of a semiconductor. independent of dimensions of conductor. independent of temperature. inversely proportional to temperature. Answer: independent of temperature. Explanation: Resistivity is property of material and inversely proportional to temperature for conductor, View Answer Discuss in Forum Report Question

 9. The speed at which the current travels, in conductor, is nearly equal to ? 4 × 10^6 m/s 3 × 10^8 m/s 3 × 10^5 m/s 3 × 10^4 m/s Answer: 3 × 10^8 m/s Explanation: View Answer Discuss in Forum Report Question

 10. Potentiometer measures potential more accurately because ? it uses high resistance potentiometer wire it measures potential in open circuit it measures potential in closed circuit it uses sensitive galvanometer for null deflection Answer: it measures potential in open circuit Explanation: Potentiometer measures potential more accurately because it measures potential in open circuit. View Answer Discuss in Forum Report Question