[{"id":123650,"question":"Thermocouple is an arrangement of two different metals","choices":[{"text":"To convert heat energy in to electrical energy","value":"A"},{"text":"To produce more heat","value":"B"},{"text":"To convert heat energy into chemical energy","value":"C"},{"text":"To convert electric energy in to heat energy","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":123649,"question":"Current provided by a battery is maximum when","choices":[{"text":"Internal resistance equal to external resistance","value":"A"},{"text":"Internal resistance is greater than external resistance","value":"B"},{"text":"Internal resistance is less then external resistance","value":"C"},{"text":"None of these","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":123647,"question":"The thermistors are usually made of","choices":[{"text":"Metals with low temperature coefficient of resistivity","value":"A"},{"text":"Metals with high temperature coefficient of resistivity","value":"B"},{"text":"Metal oxides with high temperature coefficient of resistivity","value":"C"},{"text":"Semi conducting materials having low temperature coefficient of resistivity","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":123646,"question":"In Pakistan electricity is supplied for domestic use at 220 V, it is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in Pakistan is R, the resistance of a 60 W bulb for use in USA will be","choices":[{"text":"2 R","value":"A"},{"text":"R/4","value":"B"},{"text":"R/2","value":"C"},{"text":"R","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":123645,"question":"When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be","choices":[{"text":"180 watt","value":"A"},{"text":"10 watt","value":"B"},{"text":"20 watt","value":"C"},{"text":"60 watt","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":123643,"question":"Which of the following does not obey ohm's law?","choices":[{"text":"Copper","value":"A"},{"text":"Al","value":"B"},{"text":"Diode","value":"C"},{"text":"None","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":123642,"question":"Battery is charged in motor cars, which is based on","choices":[{"text":"Chemical effect","value":"A"},{"text":"Magnetic effect","value":"B"},{"text":"Electric effect","value":"C"},{"text":"None","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":123641,"question":"The minimum resistance that can be obtained by connecting 5 resistance of 1/4Ωeach is","choices":[{"text":"4/5Ω","value":"A"},{"text":"5/4Ω","value":"B"},{"text":"20Ω","value":"C"},{"text":"0.05 Ω","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":123640,"question":"The resistance of an incandescent lamp is","choices":[{"text":"Smaller when switched on","value":"A"},{"text":"Greater when switched off","value":"B"},{"text":"The same whether it is switch off or switch on","value":"C"},{"text":"Greater when switched on","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":123639,"question":"A current of 1.6 A is passed through a solution of CuSO4. How many Cu2+ions are liberated in one minute?","choices":[{"text":"3 x 1020","value":"A"},{"text":"3 x 1010","value":"B"},{"text":"6 x 1020","value":"C"},{"text":"6 x 1010","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":123638,"question":"A heater coil rated at (1000 W - 200 V) is connected to 110 volt line. What will be the power consumed?","choices":[{"text":"200 W","value":"A"},{"text":"302.5","value":"B"},{"text":"250 W","value":"C"},{"text":"350 W","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":123637,"question":"The colour sequence in a carbon resistor in red, brown, orange and silver. The resistance of the resistor is","choices":[{"text":"21 x 103+ 10%","value":"A"},{"text":"23 x 101+ 10%","value":"B"},{"text":"21 x 103+ 5%","value":"C"},{"text":"12 x 103+ 5%","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":123636,"question":"For two resistance wires joined in parallel, the resultant resistance is 6/5 ohm. When one of the resistance wire breaks, the effective resistance becomes 2 ohm. The resistance of the broken wire is","choices":[{"text":"3/5 ohm","value":"A"},{"text":"2 ohm","value":"B"},{"text":"6/5 ohm","value":"C"},{"text":"3 ohm","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":123635,"question":"A uniform resistance wire of Length L and diameter d has a resistance R. Another wire of same material has length, 4L and diameter 2d, the resistance will be","choices":[{"text":"2 R","value":"A"},{"text":"R","value":"B"},{"text":"R/2","value":"C"},{"text":"R/4","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":123634,"question":"Calculate the amount of charge flowing in 2 minutes in a wire of resistance 10Ωwhen a potential difference of 20 V is applied between its ends","choices":[{"text":"120 C","value":"A"},{"text":"240 C","value":"B"},{"text":"20 C","value":"C"},{"text":"4 C","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":123633,"question":"106electrons are moving through a wire per second, the current developed is","choices":[{"text":"1.6 x 10-19","value":"A"},{"text":"1 A","value":"B"},{"text":"1.6 x 10-15 A","value":"C"},{"text":"106A","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":123632,"question":"The resistance of 20 cm long wire is 10Ω. When the length is changed to 40 cm. The new resistance is","choices":[{"text":"10Ω","value":"A"},{"text":"20Ω","value":"B"},{"text":"30Ω","value":"C"},{"text":"40Ω","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":123631,"question":"If two bulbs one of 60 W and other of 100 W are connected in parallel, then which one of the following will flow more?","choices":[{"text":"60 W bulb","value":"A"},{"text":"100 W bulb","value":"B"},{"text":"Both equally","value":"C"},{"text":"None of these","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":123630,"question":"Which one of the following causes production of heat when current is set up in a wire?","choices":[{"text":"Fall of electrons from higher orbits to lower orbits","value":"A"},{"text":"Inter-atomic collisions","value":"B"},{"text":"Inter-electron collisions","value":"C"},{"text":"Collisions of conduction electron with atoms","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":123629,"question":"Three resistors of resistance R each are combined in various ways. Which of the following cannot be obtained?","choices":[{"text":"3RΩ","value":"A"},{"text":"2R/4Ω","value":"B"},{"text":"R/3Ω","value":"C"},{"text":"2R/3Ω","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":123628,"question":"The resistance of the given conductor can be increased by","choices":[{"text":"Increasing the area","value":"A"},{"text":"Changing resistivity","value":"B"},{"text":"Decreasing the length","value":"C"},{"text":"None of the above because change does not matter because in any case the volume remains the same","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":123627,"question":"A 100 W, 200 V bulb is connected to a 160 volts supply. The actual power consumption would be","choices":[{"text":"64 W","value":"A"},{"text":"80 W","value":"B"},{"text":"100 W","value":"C"},{"text":"125 W","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":123626,"question":"A 60 W bulb operates on 220 V supply. The current flowing through the bulb is","choices":[{"text":"11/3 A","value":"A"},{"text":"3 A","value":"B"},{"text":"3/11 A","value":"C"},{"text":"6","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":123625,"question":"At ordinary temperature, an increase in temperature increases the conductivity of","choices":[{"text":"Conductor","value":"A"},{"text":"Semiconductor","value":"B"},{"text":"Insulator","value":"C"},{"text":"Alloy","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":123624,"question":"Potentiometer is more sensitive than voltmeter, because","choices":[{"text":"Voltmeter has a very high resistance","value":"A"},{"text":"Voltmeter has a very low resistance","value":"B"},{"text":"Potentiometer does not draw any current from a source of unknown potential difference","value":"C"},{"text":"Potentiometer is sensitive","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":123623,"question":"A car battery has e.m.f 12 volt and internal resistance 5 x 10-2ohm. If it draws 60 ampere current, the terminal voltage of the battery will be","choices":[{"text":"5 volt","value":"A"},{"text":"3 volt","value":"B"},{"text":"15 volt","value":"C"},{"text":"9 volt","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":123622,"question":"Specific resistance of a wire depends upon","choices":[{"text":"Length","value":"A"},{"text":"Cross-section area","value":"B"},{"text":"Mass","value":"C"},{"text":"None","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":123621,"question":"Cause of heat production in a current carrying conductor is","choices":[{"text":"Collisions of free electrons with one another","value":"A"},{"text":"High drift speed of free electrons","value":"B"},{"text":"Collisions of free electrons with atoms or ions of conductor","value":"C"},{"text":"High resistance value","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":123620,"question":"In a building, there are 15 bulbs of 40 watts, 5 bulbs of 100 watts, 5 fans of 80 watts and a heater of 1 kilowatt. The voltage of the electric main is 220 volts. The minimum efficiency of the main fuse of the building will be","choices":[{"text":"0.4 A","value":"A"},{"text":"11.4 A","value":"B"},{"text":"9.8 A","value":"C"},{"text":"10.6 A","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":123619,"question":"The powers of tow electric bulbs are 100 W and 200 W. Both of them are joined with 220 V mains. The ratio of resistances of their filaments will be","choices":[{"text":"1 : 2","value":"A"},{"text":"2 : 1","value":"B"},{"text":"1 : 4","value":"C"},{"text":"4 : 1","value":"D"},{"value":"E"}],"correctAnswer":2}]