Question

Батарейка с ЭДС=10 В при силе тока 0,5 А отдает во внешнюю цепь мощность 2,5 Вт. Какую мощность будет отдавать эта батарейка во внешнюю цепь при силе тока 0,2 А?

Answer 1

Calculation of Power

To calculate the power, we can use the formula:

Power (P) = Voltage (V) x Current (I)

Given that the battery has an electromotive force (EMF) of 10 V and a current of 0.5 A, and it delivers a power of 2.5 W to the external circuit, we can calculate the resistance of the external circuit using the formula:

Resistance (R) = Voltage (V) / Current (I)

Let's calculate the resistance first:

Resistance (R) = 10 V / 0.5 A = 20 Ω Now, we can calculate the power delivered by the battery when the current is 0.2 A using the formula:

Power (P) = Voltage (V) x Current (I)

Power (P) = 10 V x 0.2 A = 2 W

Therefore, the battery will deliver a power of 2 W to the external circuit when the current is 0.2 A.