Kirchhoff's junction rule is a reflection of:
a. | conservation of the current density vector |
b. | conservation of charge |
c. | the fact that the momentum with which a charged particle approaches a junction is unchanged (as a vector) as the charged particle leaves the junction |
d. | the fact that there is no accumulation of charges at a junction |
Which of the above statements are correct?
1. b and c
2. a and c
3. b and d
4. c and d
A cell having an emf ε and internal resistance r is connected across a variable external resistance R. As the resistance R is increased, the plot of potential difference V across R is given by:
1. | 2. | ||
3. | 4. |
Which of the following graph represents the variation of resistivity () with temperature (\(T\)) for copper?
1. | 2. | ||
3. | 4. |
The dependence of resistivity \((\rho)\) on the temperature \((T)\) of a semiconductor is, roughly, represented by:
1. | 2. | ||
3. | 4. |
Which of the following \((\text{I-V})\) graphs represents ohmic conductors?
1. | 2. | ||
3. | 4. |
Figure (i) and figure (ii) both are showing the variation of resistivity \((\rho)\) with temperature (T) for some materials. Identify the type of these materials.
1. | conductor and semiconductor |
2. | conductor and Insulator |
3. | insulator and semiconductor |
4. | both are conductors |
Assertion (A): | The fractional error in R is most affected by that of the smallest resistance in the combination, other things being equal. |
Reason (R): | In parallel, the conductances add. The contribution to the overall error in the conductance is largest for the largest conductance or the smallest resistance. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
1. | \( {i}_{0}T\) | 2. | \( \frac{{i}_{0}T}{2}\) |
3. | \( \frac{{i}_{0}T}{3}\) | 4. | \( \frac{{i}_{0}T}{\sqrt{2}}\) |
Assertion (A): | Resistance of a conducting metallic wire depends on the voltage applied across it and current passing through it. |
Reason (R): | Ohm's law is also valid for semiconductors. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |