In the circuit shown below, $R_1=4,R_2=5,R_3=10,R_4=5,$ and $V=18V.$ Find the power dissipated by $R_1.$

Answer

Three resistors connected in parallel have individual values of $4\mathrm{.}0,6\mathrm{.}0$ and $10\mathrm{.}0$ Ohms, respectively. This combination is connected in series with a $12-V$ battery and a $2\mathrm{.}0$ Ohm resistor. a$)$ What is the current in the $4\mathrm{.}0-$Ohm resistor? b$)$ What is the current in the $10-$Ohm resistor?

a$.$ Answer: $q,$

b$.$ Answer:

An electron is accelerated from rest by a potential difference of $350$ V $.$ It then enters a uniform magnetic field of magnitude $200$ mT with its velocity perpendicular to the field. Calculate the number of revolutions completed by the electron in $2$ seconds. $($me$-31$ kg and $e=1\mathrm{.}610-19C).$

Answer:

A wire with linear density $($mass per unit length$)$ of $1$gra$\frac{m}{c}m$ is placed on a horizontal surface with a coefficient of kinetic friction of $0\mathrm{.}20.$ The wire carries a current of $1\mathrm{.}50$ A eastward. In a vertical magnetic field, the wire moves horizontally to the north with a constant speed of $4\mathrm{.}2\frac{m}{s}.$ a$)$ What is the magnitude of the vertical magnetic field that enables the wire to move in this fashion? b$)$ A$,$ what is the magnitude of the magnetic field acting on the electrons$/$current$?$

a$.$ Answer:

b$.$ Answer: