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## Current Electricity ### 2016 #### 55. Draw the circuit diagram to measure the potential difference across a 10Ω resistor when it is connected in series with a 20Ω resistor and a 6V source. #### 56. A copper wire of 2.5 x 10^-6m² area carries a current of 1.6A. If the number density of the ele...
## Current Electricity ### 2016 #### 55. Draw the circuit diagram to measure the potential difference across a 10Ω resistor when it is connected in series with a 20Ω resistor and a 6V source. #### 56. A copper wire of 2.5 x 10^-6m² area carries a current of 1.6A. If the number density of the electrons in the wire is 8 x 10^28/m³, then calculate the drift speed of the electrons in the wire. (e=1.6 x 10 ^-19C) #### 57. 5 cells, each of emf 1.5V and internal resistance 0.1Ω, are connected in such a manner that the current in an external resistor of 10Ω is maximum. Draw the circuit diagram of the combination and calculate the current in the circuit. ### 2017 #### 58. The potential difference between the ends of a uniform conductor in a circuit is V. If J is the current density in the conductor and l and A are its length and area of cross section respectively, then the resistivity ρ of its material is * VIJ/A * J/V * Vl/J * V/J #### 59. Define mobility of the charge carries in a conductor. #### 60. The current in a resistor varies with time according to the equation I=5A+2AS^-1t. Calculate how many coulomb pass through the cross section of the resistor in the time interval between t=2s and t=5s. #### 61. Deduce the dimension of the resistivity of a material. #### 62. Calculate i in the given circuit applying kirchhoff's laws. * A circuit diagram consisting of a 6Ω resistor, 2Ω resistor and 12Ω resistor connected in parallel with a 6V battery is shown. i1 is shown flowing through the 6Ω resistor and 12Ω resistor in series, and i2 is shown flowing through the 2Ω resistor. ### 2018 #### 63. The variation of resistivity of a material with absolute temperature T is given by the following figure. The material is a (Fill in the blanks using conductor or semiconductor) * A plot of resistivity ρ against temperature T is shown. Resistivity decreases with increasing temperature.
