When no current is drawn through an electrochemical cell, the difference of the electrode potentials of the two electrodes is called cell emf. True or False?

Consider the following statements The equivalent emf is equal to the individual emf of the cells in the series combination of cells having the same emf. The equivalent emf is equal to the individual emf of the cells in the parallel combination of cells having the same emf. Which of the following statement is correct?

A

Only 1

B

Only 2

C

Both 1 and 2

D

Neither 1 and 2

তড়িৎদ্বার দুটির বিজারণ বিভব যথাক্রমে -0.76 V এবং +0.80 V । এই তড়িৎদ্বার দুটি দ্বারা তৈরি কোষের মোট বিভব কত? (The reduction potentials of two electrodes same are -0.76 V and +0.80 V, respectively. what is the EMF of a cell constructed using these two electrodes?)

A

-0.04 V

B

+0.04 V

C

-1.56 V

D

+1.56 V

Standard reduction potentials of the two electrodes Co2+/Co and Fe2+/Fe are -0.28 V and -0.44 V respectively. The EMF of the cell for which cell reaction is Co + FE2+ → Co2+ + Fe will be

A

-0.16 V

B

-0.72 V

C

+0.72 V

D

+0.16 V

Which of the following statements are true about a fuel cell? (A) It is a device that uses electrochemical reactions to produce electric current (B) It consists of a positive electrode and a negative electrode separated by an electrolyte (C) Just like batteries it needs to be recharged With an electric current Choose the correct option from those given below:

A

(A) and (B) only

B

(B) and (C) only

C

(A), (B) and (C)

D

None

Which of the following is a correct method to calculate the EMF of a galvanic cell? + b) Standard EMF of the cell = – c) E°cell = E°cathode – E°anode d) Standard EMF of the cell = +

A

Standard EMF of the cell = +

B

Standard reduction potential of the reduction half reaction

C

Standard reduction potential of the reduction half reaction

D

Standard reduction potential of the reduction half reaction

A thermocouple-based temperature measurement system is shown in the adjoining figure. Relevant thermocouple emf data (in mV) is given below. The cold junction is kept at 0°C. The temperature is 30°C in the other parts of the system. The emf V is measured to be 26.74 mV. Th temperature of the hot liquid is Temp. emf of Chromel- Constantan emf of Copper- Constantan 10°C 0.591 0.391 20°C 1.192 0.789 30°C 1.801 1.196 370°C 26.549 19.027 380°C 27.345 19.638

A

370.0°C

B

372.4°C

C

376.6°C

D

380.0°C

Which of the following statement about fuel cells are correct? Statement 1: In the cell, hydrogen and oxygen are bubbled through porous carbon electrodes into a concentrated aqueous sodium hydroxide solution. Statement 2: Catalysts like finely divided platinum or palladium metal are incorporated into the electrodes for increasing the rate of electrode reactions.

A

Statement 1 is correct

B

Statement 2 is correct

C

Both are correct

D

Both are incorrect

Two processes X and Y need to access a critical section. Consider the following synchronization construct used by both the processes Process ? /* other code for process ? */ while(true) { varP = true; while(varQ == true) { /* Critical Section */ varP = false; } } /* other code for process ?? */ Process ? /* other code for process ? */ while(true) { varQ = true; while(varP == true) { /* Critical Section */ varQ = false; } } /* other code for process ? */ Here, varP and varQ are shared variables and both are initialized to false. Which one of the following statements is true?

A

The proposed solution prevents deadlock but fails to guarantee mutual exclusion

B

The proposed solution guarantees mutual exclusion but fails to prevent deadlock

C

The proposed solution guarantees mutual exclusion and prevents deadlock

D

The proposed solution fails to prevent deadlock and fails to guarantee mutual exclusion

All electrode potentials are measured with respect to which reference electrode?

A

hydrogen electrode

B

platinum electrode

C

calomel electrode

D

hydrogen absorbed on platinum electrode

Consider the following statements.
1. All valid arguments contain only true premises and a true conclusion.
2. Some valid arguments contain only false propositions - false premises and a true conclusion.
3. All valid arguments contain only false propositions all premises are false, conclusion is false as well.
Which of the above statements is correct?

A

Only 1

B

Only 1

C

Only 3

D

None of these

When no current is drawn through an electrochemical cell, the difference of the electrode potentials of the two electrodes is called cell emf. True or False?

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