Download a) Electric current, b) One Ampere current, c

Electricity 1. Define the following : a) Electric current, b) One Ampere current, c) Electric circuit, d) Conventional direction of 2.
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electric current, e) Electric potential, f) Potential difference, g) One Volt potential difference, h) Resistance, i) Conductors, j) Insulators, k) Resistivity, l) Electric power. Differentiate between : a) Charge and current, b) Conductors and insulators, c) Resistance and resistivity, d) Resistances in series and resistances in parallel. Derive expressions for : a) Resistances in series, b) Resistances in parallel, c) Ohm's law, d) Joule's law, f) Electric power in Calories. State the following : a) Ohm's law, b) Joule's law of heating Give reasons : a. No current flows through metal wire when there is no potential difference across its ends. b. Heat is generated when current flows through a metal wire. c. Argon and Nitrogen are filled in electric bulbs. d. Mica sheet is used to cover the heating coil in an iron. e. Copper and Aluminium wires are used in domestic electrical fittings. f. The material used for making fuse has a low melting point. g. The material used for making bulb filament has a high melting point. h. Wood and glass are good insulators. i. The effective resistance of the combination of resistors in parallel is lesser than each individual resistor in the combination. j. Current flowing through given resistance increases as the potential difference across its ends is increased. k. Metals are good conductors of electricity. Draw symbols for : a) An electric cell, b) Tap key in off position, c) Tap key in on position, d) Electric bulb, e) Resistor, f) Voltmeter, g) Ammeter. Solve the following : a. An electric current of 0.5 A is flowing through a resistance for 1 minute. Find the charge that is flowing through it. b. A charge of 20 C is flowing through the circuit for 25 s. Find the current. c. What is the amount of work done in moving 5 C charge through a potential difference of 10 V? d. If 100 J of work is done in moving 10 C charge from one point to other, find the potential difference. e. Find the current flowing through a bulb filament having 1.2 KΩ resistance if the bulb is supplied 230 V. f. Find the resistance of an iron coil if 0.2 A current flows through it when a potential difference of 230 V is applied across it. g. Find the resistance of a 10 m copper wire having 0.1 cm diameter of the cross‐section. ρCopper=1.62×10‐8Ωm. h. Find the resistance of following systems : a) , b) i. Find the power of the bulb if 0.2 A current flows through it when a potential difference of 220 V is applied across its ends. j. An electric heater is rated 1500 W. Find the monthly electric bill of the heater (30 days) if it is used for half an hour every day (cost of a unit = Rs. 4) k. Find the heat generated in joules if an iron of 1200 Ω resistance is supplied 220 V for 10 s. l. How will you connect three 10 Ω resistances to give an effective resistance of a) 15 Ω, b) 3.33 Ω © MahaEduTechNet Team