Exam 1: Voltage, Current, Power, and Sources

Plot -f(t)=2tu(t)-6(t-2)u(t-2)+8(t-4) u(t-4)-12(t-7)u(t-7)+8(t-8) u(t-8)

the power in the circuit element shown below and state whether the element is absorbing power or releasing power.

Plot - $f ( t ) = 3 \operatorname { tri } \left( \frac { t - 2 } { 6 } \right)$

the power instantaneous p(t) on the element when the current i(t) through the element from positive terminal to negative terminal and voltage v(t) across the element are given by $\mathrm { i } ( \mathrm { t } ) = 12 \cos \left( 2 \pi 50 \mathrm { t } + 50 ^ { \circ } \right) \mathrm { A } , \mathrm { v } ( \mathrm { t } ) = 210 \cos \left( 2 \pi 50 \mathrm { t } + 75 ^ { \circ } \right) \mathrm { V }$

Plot - f(t)=4 σ (t+6)- 5 σ (t-4)

charge entering an element is shown below. Plot the current through the element for 0 ≤ t < 10s.

Plot -f(t) = -2u(t) + 6 u(t-2) - 9 u(t-5) + 5 u(t-8)

Plot -v(t) = 3 + 8 cos(2π2000t + 135°) V

Plot - $f ( t ) = - 3 \operatorname { rect } \left( \frac { t - 4 } { 6 } \right)$

the equation of the sinusoid shown below.