# Electric Current One Liner Questions & Answers

 Questions Answers 1 A 100-watt electric bulb is used for 10 hours. What will be the cost of electricity consumed, if the consumption cost is Rs. 5 per unit? Rs. 5 2 If a bulb of 100 watt burns for 10 hours, the expenditure of electricity will be – 1 unit 3 Five bulbs each of 100-watt capacity in a tunnel are illuminated continuously for twenty hours. The consumption of electricity will be – Ten units 4 The value of 1 kilowatt hour is – 3.6 × 106J 5 An electric bulb of 100 watts is used for 4 hours. The unit of electric energy used is – 0.4 6 How many units of electricity will be consumed if you use a 60-watt electric bulb for 5 hours every day for 30 days? 9 7 An electric bulb is connected to a 220 v generator. The current is 0.5 A. The power of the bulb is – 110 w 8 The total resistance of a circuit having two parallel resistors is 1.403 kilo-ohm. If one of the resistors is 2.0 kilo-ohm, then the other resistor will be – 4.70 kilo-ohm 9 A dynamo which is said to generate electricity actually acts as a – Converter of energy 10 ‘Dynamo’ is a device, which converts – Mechanical energy into electrical energy 11 When electrical energy is converted into motion – There is no heat loss 12 A device which converts electrical energy into mechanical energy is – Electric motor 13 The device which works on the principle of electromagnetic induction is – Dynamo & Electric motor 14 A device which converts chemical energy into electrical energy is called – Battery 15 Electric motors operating at low voltages tend to burn out because – They draw more current which is inversely proportional to the voltage 16 Faraday constant – Is a universal constant 17 Which metals are used as filaments in lighting bulbs? Tungsten 18 The temperature of the filament of lighted electric bulb is generally – 2000oC to 2500oC 19 Lightning can even burn a tree because it contains tremendous amount of – Electric energy 20 In a three-pin electrical plug longest pin should be connected to – Ground terminal 21 In electric apparatus ‘earth’ is used – For safety 22 The electric current does not flow between two properly connected charged bodies if they are having – Same potential 23 The principle of fuse is – Heating effect of electricity 24 A fuse wire is characterized by – High resistance and low melting point 25 The filament of a halogen lamp is an alloy of – Tungsten and sodium 26 Domestic electrical wiring is basically a – Parallel connection 27 A wire with black insulation during electric supply is– Neutral wire 28 What is the order of magnitude of electric resistance of the human body (dry)? 104 ohm 29 Full form of C.F.L. is – Compact Fluorescent Lamp 30 Light Emitting Diode (LED) work on principle of – Electroluminescence 31 What gases are filled in fluorescent tube? Mercury and neon 32 How does the white light produce in the tube? By oscillating the molecules 33 Fluorescent tubes are filled with a choke. The choke coil – Steps up the line voltage 34 If potential difference and current flowing through a wire is increased twice each then electric power – Will increase four times 35 Two wires have their lengths, diameters, and resistivity all in the ratio of 1: 2. If the resistance of the thinner wire is 10 ohm, the resistance of the thicker wire is – 10 ohm 36 Small drops of the same size are charged to V volts each. If n such drops coalesce to form a single large drop, its potential will be – N2/3 V 37 The transformer is used for – To step-up or step-down AC voltages 38 A mobile phone charger is – A step down transformer 39 The basic difference between an AC generator and a DC generator is that – The AC generator has slip rings while the DC generator has a commutator 40 Alternate current is not preferable – To charge storage battery 41 The device used for converting alternating current to direct current is called – Rectifier 42 The earth’s magnetic field is due to – Currents circulating inside the core 43 What is the source of electrical energy in an artificial satellite? Solar cells 44 Which elements are used in solar cells? Silicon 45 Photovoltaic cells are – Solar cells 46 Photovoltaic cells are related to – Solar Energy