Consider the following statements: 1. Superconductors exhibit normal conductivity behaviour above a transition temperature Tc 2. Superconductors lose their superconducting nature in an external magnetic field, provided the external magnetic field is above a critical value. 3. High Tc, superconductors have T, values in the range 1 to 10 K. Which of the above statements are correct?

1 and 2 only
1 and 3 only
2 and 3 only
1, 2 and 3

LohaHridoy

4 views

2025-01-04 04:42

1 Answers

AhmedNazir

Option 1 : 1 and 2 only

For temperature above transition temperature T_c a superconductor transforms to normal conductor.
When applied magnetic field is greater than the critical magnetic field H > H_c a super conductor becomes a normal conductor.
High T_c super conductors have T_c > 50° K

4 views Answered 2022-09-04 04:29

Related Questions

Consider the following statements: 1. The operation of a refrigerator unit at more than one temperature can be accomplished by using different throttling valves and a separate compressor for each ‘temperature range’. 2. The refrigerated space must be maintained above the ice point to prevent freezing. 3. In domestic refrigerators, the refrigerant is throttled to a higher pressure in the freezer followed by full expansion in the refrigerated space. Which of the above statements are correct ?

1 Answers 6 Views

Consider the following statements: 1. The entropy of a pure crystalline substance at absolute zero temperature is zero. 2. the efficiency of a reversible heat engine is independent of the nature of the working substance and depends only on the temperature of the reservoirs between which it operates. 3. Carnot’s theorem states that of all heat engines operating between a given constant temperature source and a given constant temperature sink, none has a higher efficiency than a reversible engine Which of the above statements are correct?

1 Answers 6 Views

Consider the following statements: 1. A high aggregate impact value indicates strong aggregates. 2. A low aggregate crushing value indicates high crushing strength of aggregates. 3. Aggregates having elongation index values greater than 15% are generally considered suitable for pavement construction. 4. Flakiness index of aggregates should not be less than 25% for use in road construction. Which of the above statements are correct ?

1 Answers 8 Views

Which of the following statements are correct for superconductors 1. A substance loses its electrical resistance below a certain temperature. 2. Superconducting elements have greater electrical resistivity at room temperature. 3. On adding impurities to superconducting elements its transition temperature is increased.?

1 Answers 4 Views

Consider the following statements about thermal conductivity: 1) Thermal conductivity decreases with increasing molecular weight 2) Thermal conductivity of non-metallic liquids generally decreases with increasing temperature 3) Thermal conductivity of gases and liquids is generally smaller than that of solids Which of the above statements are correct?

1 Answers 5 Views

Consider the following statements: For a component made of ductile material, the failure criterion will be 1. endurance limit, if the external force is fluctuating 2. fatigue, if the external force is fluctuating 3. yield stress, if the external force is static Which of the above statements are correct?

1 Answers 4 Views

Consider the following statements: 1) At low Reynolds numbers of any flow, viscous forces dominate over inertial forces. 2) Transition from laminar to turbulent flow occurs over a range of Reynolds numbers depending on the surface presented to the flow. Which of the above statements is/are correct?

1 Answers 5 Views

Consider the following statements: 1. Heat treatment is effective only in case of certain alloys. 2. Cooling rate is an important factor in any heat treatment process. 3. The temperature at which the change starts on heating the steel is called lower critical temperature. Which of the above statements are correct?

1 Answers 4 Views

In transition boiling, heat flux decreases due to which of the following 1. Low value of film heat transfer coefficient at the surface during 100°C to 120°C surface temperature. 2. Major portion of heater surface is covered by vapour film which has smaller thermal conductivity as compared to liquid. 3. Nucleate boiling occurs very fast. Select the correct answer using the code given below.?

1 Answers 5 Views

In the following question, the 1st and the last part of the sentence/passage are numbered 1 and 6. The rest of the sentence/ the passage is split into four parts and named P, Q, R and S. These four parts are not given in their proper order. Read the sentence/ passage and find out which of the four combinations is correct. 1. Carbon-intensive firms are likely to lose 43% of their value thanks to policies designed to combat climate change, a report says. P. Representatives of fossil fuel companies told the BBC they were already adapting their businesses to take climate change into account. Q. But the PRI study suggests major winners and losers will emerge between, and within, big sectors. Car-makers with the swiftest transition to electric vehicles (EVs), for instance, are projected to increase in value by 108%, according to the study by Vivid Economics. R. The forecast was commissioned by the UN-backed Principles for Responsible Investment (PRI). S. Meanwhile the most progressive companies will see an uplift of 33% in their value. 6. Manufacturers slow to move to EVs will see their value fall, as governments realize that petrol and diesel models must be phased out faster for climate targets to be met.?

1 Answers 5 Views

এক্সাম দিয়ে মেধা যাচাই করুন

Job Preparation (1125)

Admission (754)

এসএসসি (10)

এইচএসসি (5)