Question

Электролампа , сопротивление нити накала 20 Ом , включена в сеть с напряжением 220 В .Какова мощность тока?Какую работу он произведет за 5 мин свечения лампы?

Answer 1

1) P = U * I 

U - напряжение ( 220 В ) 
I - сила тока 

I = U / R 

U = 220 B 
R - сопротивление ( 20 Ом ) 

I = 220 / 20 = 11 A 

P = U * I = 220 * 11 = 2420 Вт 

P = A / t -----------------------> A = P * t 

P = 2420 Вт 
t = 5 мин = 300 c 

A = 2420 * 300 = 726000 Дж = 726 кДж 

Answer 2

Calculation of Current and Power

To calculate the current and power of the lamp, we can use Ohm's Law and the formula for power.

The resistance of the filament is given as 20 Ohms, and the voltage of the network is 220 Volts.

According to Ohm's Law, the current (I) can be calculated using the formula:

I = V / R

where: - I is the current in Amperes (A) - V is the voltage in Volts (V) - R is the resistance in Ohms (Ω)

Substituting the given values, we have:

I = 220 V / 20 Ω

Calculating this, we find:

I = 11 A

Therefore, the current flowing through the lamp is 11 Amperes.

To calculate the power (P) of the lamp, we can use the formula:

P = V * I

where: - P is the power in Watts (W) - V is the voltage in Volts (V) - I is the current in Amperes (A)

Substituting the given values, we have:

P = 220 V * 11 A

Calculating this, we find:

P = 2420 W

Therefore, the power of the lamp is 2420 Watts.

Calculation of Work Done

To calculate the work done by the lamp during 5 minutes of operation, we need to use the formula for work:

Work = Power * Time

where: - Work is the work done in Joules (J) - Power is the power in Watts (W) - Time is the time in seconds (s)

Given that the lamp operates for 5 minutes, we need to convert this to seconds:

Time = 5 minutes * 60 seconds/minute

Calculating this, we find:

Time = 300 seconds

Substituting the values into the formula, we have:

Work = 2420 W * 300 s

Calculating this, we find:

Work = 726,000 J

Therefore, the lamp will produce 726,000 Joules of work during 5 minutes of operation.

Please note that the calculations provided are based on the given information and assumptions.