Question

Consider the following. (a) A rectangular block has the dimensions { x W x h. When a battery with a voltage AV is connected across the end faces as shown in the left figure above, a current 1; flows through the circuit. If the same battery is connected across the top and bottom faces of the block as shown in t right figure, what is the current 1, that flows through the circuit? Give your answer in terms of I.. (Use the following as necessary: /', w, h, and 1.) X What is the resistance for the two cases? How does Ohm's law relate current to voltage? (b) Suppose { = 4.80 cm, w = 2.2 ern, and 1 = 1.80 cm; the battery voltage is 1.5 V and 1 = 2.90 A, determine the value of 17- A

Answer 1

a) Griven: R=SL se (A = Wh For first care Length = 1 Area = Wxh For second case length = h Area = wol Let for first case, resistance of block is, : Lut A wh . From Ohms law, we have, AV=I, RI I, = Ri AV -. - AV T = AV wh St -(1) 81 in second case, we have R₂=SL sh A=we From Ohms law, we have 3h AV = IzB = DV=Iz ( we substituting given av in eqh. (4), we have, I = I (sh) x wh (:3,-8,-5) Wh similarly A We (Lih . I = I h² 12 (2) Let, 1=4.808152m W=2.2x10-2 h=1.80818-2m Ar=1.5 V m I=2.90 Iz = ? . From equation (2), we have 4.80X10-21 Iz = X 2.90 1.80x102 In=216.4838A