Answer : The correct option is, (b) Thermometer B, because it measures temperature more accurately than A.
Explanation :
Accuracy : It is defined as the closeness of a measured value to a standard or known value.
For Example: If the mass of a substance is 50 kg and one person weighed 48 kg and another person weighed 55 kg. Then, the weight measured by first person is more accurate.
Precision : It is defined as the closeness of two or more measurements to each other.
For Example: If you weigh a given substance five times and you get 1.8 kg each time. Then the measurement is said to be precise.
Level of precision is determined by the maximum number of decimal places.
As per question, the thermometer B has markings 40°, 45° and 50° at equal intervals and there are four small markings equally spaced in between the numbers and thermometer B has markings 40°, 45° and 50° at equal intervals but there is no small markings equally spaced in between the numbers. That means, thermometer B is measures temperature more accurately than thermometer A.
Hence, correct option is, (b) Thermometer B, because it measures temperature more accurately than A.
Answer:
Correct answer: P₂ = 25 W
Explanation:
Given: voltage V₁ = 220 V, power P₁ = 100 W, V₂ = 110 V, P₂ = ?
The formula for calculating power is:
P = V · I
We will include in the story and ohm's law:
I = V/R
We will replace the current in the expression for power
P = V · V/R = V²/R ⇒ R = V²/P
We will first calculate the electrical resistance of the bulb which is a constant in the electrical circuit
R = V₁²/P₁ = 220²/ 100 = 48,400 / 100 = 484 Ω
Power consumption of bulb connected to 110 V is:
P₂ = V₂²/R = 110²/484 = 12,100/484 = 25 W
P₂ = 25 W
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