Question

A small toy car draws a 0.50-mA current from a 3.0-V NiCd battery. In 10 min of operation, (a) how much charge flows through the toy car, and (b) how much energy is lost by the battery? 4. (Resistance and Ohm’s law, Prob. 17.16, 1.0 point) How

Answer 1

(a) 0.3 C

(b) 0.9 J

Step-by-step explanation:

(a)

Given:

Current drawn (I) = 0.50 mA = 0.50 × 10⁻³ A

Terminal voltage (V) = 3.0 V

Time of operation (t) = 10 min = 10 × 60 = 600 s

Charge flowing through the toy car 'Q' is given as:

`Q=It`

Plug in the given values and solve for 'Q'. This gives,

`Q=(0.50* 10^(-3)\ A)(600\ s)\\\\Q=0.3\ C`

Therefore, 0.3 C charge flows the toy car.

(b)

Energy lost by the battery is equal to the product of power consumed by the battery and time of operation.

Power consumed by the battery is given as:

`P=VI`

Plug in the given values and solve for 'P'. This gives,

`P=(3.0\ V)(0.50* 10^(-3)\ A)\\\\P=1.5* 10^(-3)\ W`

Therefore, the energy lost by the battery is given as:

`E=P* t\\\\E=1.5* 10^(-3)\ W* 600\ s\\\\E=0.9\ J`

Therefore, the energy lost by the battery is 0.9 J