Advertisements
Advertisements
प्रश्न
Is neutral temperature always the arithmetic mean of the inversion temperature and the temperature of the cold junction? Does the unit of temperature have an effect in deciding this question?
Advertisements
उत्तर
No, the neutral temperature is not always the arithmetic mean of the inversion temperature and the temperature of the cold junction. That is valid only when the unit of temperature is degree Celsius.
APPEARS IN
संबंधित प्रश्न
A silver wire has a resistance of 2.1 Ω at 27.5°C, and a resistance of 2.7 Ω at 100°C. Determine the temperature coefficient of resistivity of silver.
The order of coloured rings in a carbon resistor is red, yellow, blue and silver. The resistance of the
carbon resistor is:
a) 24 x 106 Ω ± 5%
b) 24 x 106 Ω ± 10%
c) 34 x 104 Ω ± 10%
d) 26 x 104 Ω ± 5%
Draw labelled graphs to show how electrical resistance varies with temperature for:
1) a metallic wire.
2) a piece of carbon
The thermal energy developed in a current-carrying resistor is given by U = i2 Rt and also by U = Vit. Should we say that U is proportional to i2 or i?
Consider a circuit containing an ideal battery connected to a resistor. Do "work done by the battery" and "the thermal energy developed" represent two names of the same physical quantity?
Sometimes it is said that "heat is developed" in a resistance when there is an electric current in it. Recall that heat is defined as the energy being transferred due to temperature difference. Is the statement in quotes technically correct?
Two resistors R and 2R are connected in series in an electric circuit. The thermal energy developed in R and 2R are in the ratio ______________ .
When a current passes through a resistor, its temperature increases. Is it an adiabatic process?
As temperature increases, the viscosity of liquids decreases considerably. Will this decrease the resistance of an electrolyte as the temperature increases?
Consider the following statements regarding a thermocouple.
(A) The neutral temperature does not depend on the temperature of the cold junction.
(B) The inversion temperature does not depend on the temperature of the cold junction.
An electric kettle used to prepare tea, takes 2 minutes to boil 4 cups of water (1 cup contains 200 cc of water) if the room temperature is 25°C. (a) If the cost of power consumption is Re 1.00 per unit (1 unit = 1000 watt-hour), calculate the cost of boiling 4 cups of water. (b) What will be the corresponding cost if the room temperature drops to 5°C?
Find the neutral temperature and inversion temperature of a copper-iron thermocouple if the reference junction is kept at 0°C. Use the data given in the following table.
| Metal with lead (Pb) |
a `mu V"/"^oC` |
b `muV"/("^oC)` |
| Aluminium | -0.47 | 0.003 |
| Bismuth | -43.7 | -0.47 |
| Copper | 2.76 | 0.012 |
| Gold | 2.90 | 0.0093 |
| Iron | 16.6 | -0.030 |
| Nickel | 19.1 | -0.030 |
| Platinum | -1.79 | -0.035 |
| Silver | 2.50 | 0.012 |
| Steel | 10.8 | -0.016 |
A metallic wire has a resistance of 3.0 Ω at 0°C and 4.8 Ω at 150°C. Find the temperature coefficient of resistance of its material.
Water at 10°C enters into a geyser. The water drawn out from the geyser has a temperature of 60°C and the rate of outflow of water is 18 kg/hr. The rating of the geyser is :
Temperature dependence of resistivity ρ(T) of semiconductors, insulators and metals is significantly based on the following factors:
- number of charge carriers can change with temperature T.
- time interval between two successive collisions can depend on T.
- length of material can be a function of T.
- mass of carriers is a function of T.
