When no current is passed through a conductor,

a.	the free electrons do not move.
b.	the average speed of a free electron over a large period of time is zero.
c.	the average velocity of a free electron over a large period of time is zero.
d.	the average of the velocities of all the free electrons at an instant is zero.

Choose the correct option: 
1. (a) only 
2. (b), (c) 
3. (c), (d) 
4. (a), (d) 

Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?

Choose the correct option: 
1. (d) only 
2. (b), (c) 
3. (c), (d) 
4. (a), (d) 

As the temperature of a conductor increases, its resistivity and conductivity change. The ratio of resistivity to conductivity:

Choose the correct option:
1. (a) only 
2. (b), (c) 
3. (c), (d) 
4. (a), (d) 

(a) the charge crossing in a given time interval
(b) drift speed
(c) current density
(d) free-electron density

Choose the correct option 

1. (a) only

2. (b), (c)

3. (c), (d)

4. (a), (d)

Choose the correct option
1. (a) only

2. (b), (c)

3. (c), (d)

4. All of these

1. \(a\)
2. \(b\)
3. \(c\)
4. \(d\)

1.  a

2.  b

3.  c

4.  d

Consider the following statements regarding a thermocouple.

The heat developed in a system is proportional to the current through it.

1.  It cannot be Thomson heat.

2.  It cannot be Peltier heat.

3.  It cannot be Joule heat.

4.  It can be any of the three heats mentioned above.

(A) Free-electron density is different in different metals.

(B) Free electron density in a metal depends on temperature.

Seebeck effect is caused

1.  due to both A and B

2.  due to A but not due to B

3.  due to B but not due to A

4.  neither due to A nor due to B.