3. If the current flowing in a certain conductor is 40 mA. a. find the total charge in coulomb and b. find the total number of electrons that passes through the conductor in 1.8 s. (e=1.602x10- 19C/electrons)

Jimmy has a battery connected across a peice of conducting wire. If Jim wants to create greater power dissipation in the wire , he should : a. Make the wire longer b. Increase the diameter of the wire cross section  c. Increase the resistivity of the wires matierial d. Increase the temperature  e. Decrease the battery voltage

11. A typical car seat heater produces 10 W of heat using a 0.25 mm diameter steel wire connected to the car's 12 V electrical system. How long is the wire? The resistivity of this particular steel is p = 4.6 × 10¬7 N.m. А. 0.50 m В. 1.0 m С. 1.5 m D. 2.0 m

5. A lamp having a resistance of 10 n is con- nected across a 15-V battery. a. What is the current through the lamp? b. What resistance must be connected in se- ries with the lamp to reduce the current to 0.50 A?

67. A metallic wire has a diameter of 4.12mm. When the current in the wire is 8.00A, the drift velocity is 5.40×10−5m/s.   What is the density of free electrons in the metal? Express the answer numerically in m−3m−3 to two significant figures.

7.5 C of charge flows for 5 seconds. Calculate the electric current (in amps).

Which of the following expression(s) represents the electrical energy stored by a capacitor? O A. QV/2 O B. CV²/2 O C. Q/2C O D. CV/2 E. Q²/2C

3. Consider a square aluminum wire with conductivity 3.5 x 10' A and side length 1.9 mm. If the electric field inside the V m wire is 2 x 10-2, what is the current in the wire? (include units)

A conductor has a cross-sectional area of 2.3x10-6 m² and the number of free electrons per unit volume is 8.5X1028 electron/m3. When the current is 12.3 A, find the drift speed (in mm/s) of the electrons. Use the charge of the electron to be 1.6X10- 19 9 С. Select one: O A. 39.32 О В. О.52 OC. 0.39 O D. 51.62 O E. 0.27

SUBJECT: PHYSICS