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Anonymous users2024-02-07The medium voltage doubles, and according to Q=(U R)t, the heat increases fourfold.
The resistance in b is increased by a factor of two, and the heat is reduced by a factor of two according to q = (u r)t.
The voltage in c is halved, and the heat is reduced by a factor of four according to Q=(U R)T.
It is correct that the resistance is halved in d, and the heat will increase by a factor of two according to q=(u r)t.
When the switch is disconnected, the voltage of the first resistor drops to the original 1 3, and according to Q=(U R)t, the heat drops by a factor of 9.
When the circuit is a purely resistive circuit, q=w=uit=i rt
When the circuit is a non-purely resistive circuit, q=i rt refers to the heat emitted, while w=uit refers to the total energy produced.
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Anonymous users2024-02-061 According to Q=i, Rt=U, and R are t, we can know that option A will be 4, and the limitation of option B is not complete, so it should be"When the current does not change, the resistance of the resistance wire is doubled"C, C will become a quarter, and D, like B, lacks qualifications, so there is no correct answer. The question stem is incomplete.
2.Let the total voltage be U, the unit resistance is R, when the switch is turned on, U is 3R, and when the switch is closed, the ratio of current is 1:3, and Q=i Rt, R, T are the same, so it is 1:9, which is B
3 It is the same in pure resistance circuits, but it is not the same in non-pure resistance circuits.
!However, the first question does not tell that the voltage or current is unchanged, and there is a problem with the question, so you can't choose blindly!
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Anonymous users2024-02-05, A: according to W=U*U R, if you are doubled, W becomes 4Wb: According to W=U*U R, R is doubled, then W becomes W 2C:
According to W=U*U R, U is halved, then W becomes W 4 When the switch is turned on and closed, the voltage changes to 1:3, and according to W=U*U R, the power changes to 1:9
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Anonymous users2024-02-04Question 1 d is Q=i rt and q=u t r
Question 2b Do you want to explain in detail?
Q=i RT and W=UIT, the first one is used for heat generation, resistance is heat generation, and this formula is used to generate Joule heating, and there is no difference between the two for resistors or pure resistance circuits. Because the work done by resistors is heat generation. But for other appliances, the two are different.
w=uit is its total energy, and q=i rt is the heat it generates.
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Anonymous users2024-02-031. D The heating power p=i i option reduces the resistance by half, the voltage remains the same, and the current is doubled, so the power is increased to twice the original.
2. The B switch is open, the two resistors are connected in series, the current is E 3R, the switch is closed, the No. 2 is short-circuited, and the current is E R. The current ratio is 1:3, and the power ratio is the square of the current ratio, so the heat ratio is 1:9
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Anonymous users2024-02-021b according to q=i rt
2bq=i rt, which is Joule's law, calculates heat.
w=uit This is used to count electricians.
Whether you can talk face-to-face is simple and troublesome.
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