A 12V car battery is rated at 70 A hr How much energy is sto

A 12V car battery is rated at 70 A hr. How much energy is stored in the battery? A 12V battery having internal resistance 0.3 ohm is connected to a 3 ohm light bulb. What is the rate at which energy is dissipated by the internal resistance? A 12V battery is attached to two corners of a triangular array of 1 ohm resistors. Find the current drawn from the battery. A 20W light bulb operates at household voltage 120V. How much current does the bulb draw?

Solution

(5) Current I = 70Ahr Voltage V=12V

Energy stored in the battery E = V*I*t = 12V*70Ahr*3600sec/hr = 3.024MJ

(6) Internal resistance r = .3 ohm Bulb resistance R = 3 ohm Voltage of battery V=12V

Current flowing through circuit I = V/(r+R) = 3.64A

(8) Power P=20W Voltage V= 120V

Current drawn I = P/V= 0.167A

energy dissipation through internal resistance = I²r =3.97W

(7) Resistors are connected in a triangular shape. First two resistors will be in series and their eqivalent resistance will be in parallel with the third one.

Equivalent resistance in series R_S =R1+R2 = 2ohm

This is in parallel with 3rd resistance So equivalent resistance R = 1/R1+1/R2=1+.5=1.5 ohm

Current drawn from battery I = V/R = 8A