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Question 26: (a) Define electric current. What is the SI unit of electric current. (b) One coulomb of charge flows through any cross-section of a conductor in 1 second. What is the current flowing through the conductor ? (c) Which instrument is used to measure electric current ? How should it be connected in a circuit ? (d) What is the conventional direction of the flow of electric current ? How does it differ from the direction of flow of electrons ? (e) A flash of lightning carries 10 C of charge which flows for 0.01 s. What is the current ? If the voltage is 10 MV, what is the energy ? Lakhmir Singh Physics Class 10 |
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Answer» a. rmelectric current is defined as the rate of flow of electric charge...s.i units....AMPERE (A)b.One coulomb is nearly equal to 6 x 1018 electrons. SI unit of electric current is ampere (A). Ampere is the flow of electric charges through a surface at the rate of one coulomb per second. This means if 1 coulomb of electric charge flows through a cross section for 1 second, it would be equal to 1 ampere.C.ampere meter...or ammeterd.The particles that carry charge through wires in a circuit are mobile electrons. The electric field DIRECTION within a circuit is by definition the direction that positive test charges are pushed. THUS, these negatively CHARGED electrons move in the direction opposite the electric field.e.Q=10 c,t=0.01 sI=Q/T=10/0.01=1000Ap.d=W/Q=W=p.d×Q =10x10^6x10 =100MJ |
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