When exploring the relationship between the current and voltage on the resistance, the sliding rheostat changes the voltage at both ends of the light bulb, while the book says that the voltage of the small light bulb is larger, There's a lot of current in the circuit, but I feel it doesn't matter

When exploring the relationship between the current and voltage on the resistance, the sliding rheostat changes the voltage at both ends of the light bulb, while the book says that the voltage of the small light bulb is larger, There's a lot of current in the circuit, but I feel it doesn't matter

In several experiments of electricity, we must make clear the object to be studied and the research methods used. When exploring the relationship between the current and voltage on the resistance, we use sliding rheostat to change the current in the bulb, and the voltage at both ends of the bulb also changes. If we use experimental observation, it is more intuitive

What is the resistance and current of normal light emission of 220 V and 100 W bulbs

The normal luminous resistance R = u ^ 2 / P = 484 Ω and current I = P / u = 0.455a for u = 220 V and P = 100 W bulbs

An incandescent lamp marked with PZ 220 100 is connected to a 110V circuit, and the influence of temperature on filament resistance is ignored to calculate the lamp's 1, rated current 2

In physics, electric power is used to express the speed of consuming electric energy. Electric power is expressed by P, and its unit is watt (WA), and the symbol is w. the work done by the current in unit time is called electric power. Take the bulb as an example, the higher the electric power is, the brighter the bulb is. The brightness of the bulb is determined by the electric power (actual power), not by the current, voltage and electric energy!
1KW＝1000W
As a physical quantity indicating the speed of energy consumption, the power of a consumer is equal to the electric energy consumed in one second (1s). If the electric energy consumed in such a long time as "t" is "W", then the electric power "P" of the consumer is "W"
P = w / T (definition) electric power is equal to the product of voltage and current (P = u · I)
1 W = 1 J / S = 1 V · a
Symbol meaning and unit
W - electric energy - Joule (J) w - kilowatt * hour (kW * h)
T-time-second (s) T-hour (H)
P - power of electric appliance - watt (W) P - kilowatt (kw)
(two sets of units, according to different needs, select the appropriate unit for calculation)
The formula of electric power is p = UI
P=I^2·R
P=U^2/R
Every electrical appliance has a normal working voltage value called rated voltage
The power of normal operation of electrical appliances under rated voltage is called rated power
The power of electrical appliances working under the actual voltage is called the actual voltage
Electric power is the speed at which the current does work at a certain time
P = w / T. because w = uit, P = UI
There are also related formulas
Relation (electric power, etc.)
(1) series circuit P (electric power) U (voltage) I (current) w (electric work) r (resistance) t (time)
The current is equal everywhere, I1 = I2 = I total
The total voltage is equal to the sum of the voltages at both ends of each consumer, u = U1 + U2
The total resistance is equal to the sum of the resistances r = R1 + R2
Partial pressure principle U1: U2 = R1: R2
The total electric work is equal to the sum of all electric works, wtotal = W1 + W2
W1：W2=R1：R2=U1：U2
P1：P2=R1：R2=U1：U2
The total power is equal to the sum of the powers P = P1 + P2
(2) parallel circuit
The total current is equal to the sum of the currents I = I1 + I2
All voltages are equal U1 = U2 = u total
The total resistance is equal to the product of the resistances divided by the sum of the resistances r = (r1r2) / (R1 + R2) 1 / r = 1 / R1 + 1 / R2
The total electric work is equal to the sum of all electric works, wtotal = W1 + W2
Shunt principle I1: I2 = R2: R1
W1：W2=I1：I2=R2：R1
P1：P2=R2：R1=I1：I2
The total power is equal to the sum of the powers, P = P1 + P2
(3) electric power of the same electrical appliance
① The ratio of rated power to actual power is equal to the square of rated voltage to actual voltage, PE / PS = (UE / US)
2. Formula of circuit
(1) resistance R
① The resistance is equal to the density of the material multiplied by (length divided by cross-sectional area) r = ρ× (L / s)
② Resistance equals voltage divided by current R = u / I
③ The resistance is equal to the square of the voltage divided by the electric power r = U2 / P
(2) electric power W
Electric work is equal to current times voltage times time w = uit (common formula)
Electric work is equal to electric power times time w = Pt
Electric work is equal to charge times voltage w = UQ
Electric work is equal to the square of current times resistance times time w = i2rt (pure resistance circuit)
Electrical work is equal to the square of voltage divided by resistance and multiplied by time w = u2t / R (same as above)
(3) electric power p
① Electric power is equal to voltage times current, P = UI
② Electric power is equal to the square of current multiplied by resistance P = I2R (pure resistance circuit)
③ The electric power is equal to the square of the voltage divided by the resistance P = U2 / R (as above)
④ Electric power is equal to electric work divided by time p = w / T
Note: when the same resistance is in the same circuit, the power will become one fourth of the previous one
(4) electric heating Q
Electric heating is equal to the square of current, which is resistance times time q = i2rt (common formula)
Electric heating equals current times voltage times time q = uit = w (pure resistance circuit)
Electric heating is equal to the square of voltage divided by resistance and multiplied by time q = (u ^ 2 / R) * t (pure resistance circuit)
Electric power of common electrical appliances
Name of electrical appliances general power (watt) estimated power consumption (KWH)
Window air conditioner 800-1300 maximum 0.8-1.3 per hour
One window type air conditioner is about 735, 0.735 per hour (other units are calculated according to the standard multiple)
Household refrigerator 65-130 about 0.65-1.73 per day
Household washing machine single cylinder 230 maximum 0.23 per hour
Double cylinder 380 maximum 0.38 Per Hour
Electric kettle 1200 1.2 per hour
Rice cooker 500 0.16 every 20 minutes
Electric iron 750 0.25 every 20 minutes
Hair dryer 450 0.04 every 5 minutes
Ceiling fan large 150 0.15 per hour
Small 75 0.08 per hour
Table fan 16 "66, 0.07 per hour
14 inch 52 per hour 0.05
TV 21 inch 70 0.07 per hour
25 inch 100 per hour 01
VCR 80 0.08 per hour
Audio equipment 100 0.1 per hour
Electric heating 1600-2000 maximum 1.6-2.0 per hour
Electronic meter 0.00001 per hour 0.00000001
Range hood 140 0.14 per hour
Microwave oven 1000 kWh
Vacuum cleaner 800 0.8 per hour
Computer 200 0.2 per hour
Flashlight 0.5 0.0005 per hour

The two bulbs are marked with "pz220-40" and "pz220-100" respectively. Try to calculate: (1) the resistance of the two bulbs; (2) the rated current of the two bulbs;
This is a question in the physics quiz. Many people are defeated in this question. Come to find an answer. There should be a process
There are three questions
The two bulbs are respectively marked with "pz220-40" and "pz220-100". Try to calculate: (1) the resistance of the two bulbs; (2) the rated current of the two bulbs; (3) when they are connected in series in the circuit, what is the maximum total voltage at both ends? What is the power of the two bulbs at this time?

1》 The resistance of the two bulbs
Pz220-40 resistance:
R＝U×U/P＝220×220/40＝1210(Ω)
Pz220-100 resistance:
R＝220×220/100＝484(Ω)
2》 Rated current of two bulbs
Rated current of pz220-40:
I＝P/U＝40/220≈0.182(A)
Rated current of pz220-100:
I＝100/220≈0.455(A)
3》 When they are connected in series, the voltage at both ends of the bulb increases
Series circuit current:
I＝U/R＝220/(1210＋484)≈0.13(A)
Voltage at both ends of pz220-40:
U＝RI＝1210×0.13≈157(V)
Voltage at both ends of pz220-100:
U＝484×0.13≈63(V)
4》 The actual power of the two bulbs at this time
Actual power of pz220-40:
P＝UI＝157×0.13≈20.4(W)
Actual power of pz220-100:
P＝63×0.13≈8.2(W)