Current Electricity and Drift Velocity

The rate of flow of charge across any cross-section of the conductor per unit time is called as electric current.

True

<p>I = dq/dt</p> Signup and view all the answers

<p>I = (ne)/t</p> Signup and view all the answers

<p>I = qω/2π</p> Signup and view all the answers

<p>I = qf</p> Signup and view all the answers

<p>Conventional current is defined as the flow of positive charge, while electronic current is defined as the flow of negative charge (electrons).</p> Signup and view all the answers

<p>Transient current is the current that remains for a short duration.</p> Signup and view all the answers

<p>The average velocity with which the free electrons are drifted towards the positive terminal under the action of the applied electric field is called as drift velocity of the free electrons.</p> Signup and view all the answers

<p>Vd = eEτ/m</p> Signup and view all the answers

<p>The distance travelled by a conduction electron during relaxation time is called as mean free path.</p> Signup and view all the answers

<p>λ = Vdτ</p> Signup and view all the answers

<p>I= neAVd</p> Signup and view all the answers

<p>The drift velocity acquired per unit electric field strength is called as mobility of the electron.</p> Signup and view all the answers

<p>μ = Vd/E</p> Signup and view all the answers

<p>I = nAμEe</p> Signup and view all the answers

<p>The electric current density at any point inside a conductor is defined as the amount of charge flowing per second through a unit area held normal to the direction of the flow of charge.</p> Signup and view all the answers

<p>J = I/A</p> Signup and view all the answers

<p>J = neVd</p> Signup and view all the answers

<p>J = σE</p> Signup and view all the answers

<p>Ohm's Law states that, 'At a constant temperature the current (I) flowing through a metallic conductor is directly proportional to the potential difference (V) between the two ends of the conductor'.</p> Signup and view all the answers

<p>V = IR</p> Signup and view all the answers

<p>Resistance is the opposition offered to the flow of electric charge in the conductor.</p> Signup and view all the answers

<p>R = V/I</p> Signup and view all the answers

<p>R = ρl/A</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>The reciprocal of resistance of a conductor is called conductance</p> Signup and view all the answers

<p>G = 1/R</p> Signup and view all the answers

<p>ρ = RA/l</p> Signup and view all the answers

<p>ρ = 1/σ</p> Signup and view all the answers

<p>σ = 1/ρ</p> Signup and view all the answers

<p>α = (Rt - Ro) / Ro * t</p> Signup and view all the answers

<p>R2 = R1[1 + α(t2 - t1)]</p> Signup and view all the answers

<p>An ohmic conductor is a conductor that obeys Ohm's law.</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>A component whose function in a circuit is to provide a specified value of resistance is called as resistor.</p> Signup and view all the answers

<p>The resistors made from carbon with a suitable binding material moulded into a cylinder are called as carbon resistor.</p> Signup and view all the answers

<p>A color code is used to indicate the value of the carbon resistance with its percentage reliability.</p> Signup and view all the answers

<p>The first system uses a set of colored co-axial rings or bands printed on the resistor, while the second system uses a body color, end color, dot color, and ring color.</p> Signup and view all the answers

<p>Potentiometer is a device to measure potential difference between two points or e.m.f. of a cell without drawing any current from the source.</p> Signup and view all the answers

<p>The potential difference between any two points of a wire of uniform area of cross-section is directly proportional to the length of the wire between these points, provided the current through the wire remains constant.</p> Signup and view all the answers

<p>The potential drop per unit length of the potentiometer wire is called as potential gradient.</p> Signup and view all the answers

<p>k = V/l</p> Signup and view all the answers

<p>A cell is a device which provides the necessary potential difference to an electric circuit to maintain a continuous flow of current in it.</p> Signup and view all the answers

<p>Two or more primary cells electrically connected and used as a single unit are called battery.</p> Signup and view all the answers

<p>The electro motive force of a cell is defined as the difference of potential between its terminals when there is no current in the external circuit.</p> Signup and view all the answers

<p>The electrolyte inside a cell between the two electrodes offers a resistance to the passage of current through it. This resistance is called as internal resistance of cell.</p> Signup and view all the answers

<p>r = R(E-V)/V</p> Signup and view all the answers

<p>The terminal potential difference of a cell is defined as the potentail difference between the two electrodes of a cell in a closed circuit i.e. when some current is drawn from the cell.</p> Signup and view all the answers

<p>V = E - Ir</p> Signup and view all the answers

<p>Electromotive force is the difference of potential between two terminals of a cell when there is no current flowing through external circuit. It is independent of the resistance of the circuit. It is a cause. Potential difference is the difference of potential between two terminals of a cell when a current flowing through external circuit. It is depend upon resistance of the circuit. It is an effect.</p> Signup and view all the answers

<p>Kirchhoff's first law (Kirchhoff's Current Law):- It states that, “The algebraic sum of currents meeting at a point (Junction) is zero”.</p> Signup and view all the answers

<p>Kirchhoff's second law (Kirchhoff's Voltage Law):- It states that, “In a closed electric circuit, the algebraic sum of e.m.f. is equal to the algebraic sum of the product of their resistances and the current flowing through them”.</p> Signup and view all the answers

<p>Wheatstone bridge is an arrangement of four resistors in the form of a bridge used for measuring one unknown resistor in terms of other three known resistors.</p> Signup and view all the answers

<p>The bridge is said to be balanced when the galvanometer shows no deflection.</p> Signup and view all the answers

<p>P/Q = R/S</p> Signup and view all the answers

<p>A meter bridge is an instrument to determine the unknown resistance of a conductor.</p> Signup and view all the answers

<p>S = R(100-l)/l</p> Signup and view all the answers

<p>ρ = SA/l</p> Signup and view all the answers

<p>The smallest potential difference that can be accurately measured by a potentiometer is called as the sensitivity of the potentiometer.</p> Signup and view all the answers

<p>A potentiometer can be made more sensitive by decreasing its potential gradient.</p> Signup and view all the answers

<p>A rheostat is a device which is used for controlling the current by varying the resistance. A potentiometer is a device which is used for controlling the current by varying the resistance..</p> Signup and view all the answers

<p>r = (k(l1-l2)R)/kl2</p> Signup and view all the answers

<p>Potentiometers offer higher sensitivity, accuracy, and do not draw current from the circuit being measured, making them superior for precision voltage measurements, especially for e.m.f. determination.</p> Signup and view all the answers

<p>The slow operation of the potentiometer and the need for uniform wire thickness and temperature stability pose some drawbacks compared to voltmeters.</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>Cells are said to be connected in series if negative terminal of first is connected with positive terminal of the second and so on. Cells are said to be connected in parallel if positive terminals of all the cells are connected at one point and negative terminals at the other point.</p> Signup and view all the answers

<p>Enet = nE</p> Signup and view all the answers

<p>rnet = nr</p> Signup and view all the answers

<p>Enet = E</p> Signup and view all the answers

<p>rnet = r/m</p> Signup and view all the answers

<p>Cells in series are particularly relevant when a higher voltage is needed in the circuit, commonly used in situations like powering a flashlight or a string of LED lights.</p> Signup and view all the answers

<p>The parallel arrangement of cells is particularly beneficial when a higher current is required, commonly used in situations like starting a car or powering a high-current electronic device.</p> Signup and view all the answers

<p>Resistors in series increase the total resistance, while resistors in parallel decrease the total resistance. Conversely, capacitors in series decrease the total capacitance, while capacitors in parallel increase the total capacitance.</p> Signup and view all the answers

<p>Req = R1*R2 / (R1+R2)</p> Signup and view all the answers