Assertion (A): | The electric bulbs glow immediately when switch is on. |
Reason (R): | The drift velocity of electrons in a metallic wire is very high. |
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. |
The plot of current \(I\) (A) flowing through a metallic conductor versus the applied voltage \(V\) (volt) across the ends of a conductor is:
1. | 2. | ||
3. | 4. |
Assertion (A): | In a meter bridge experiment null point for an unknown resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by increasing the value of the standard resistance. |
Reason (R): | Resistance of metal increases with an increase in temperature. |
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. |
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 |
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
Statement I: | Kirchoff's current law is a consequence of the conservation of energy as applied to electric circuits. |
Statement II: | Kirchoff's voltage law is a consequence of the conservation of charge. |
1. | Statement I is incorrect and Statement II is correct. |
2. | Both Statement I and Statement II are correct. |
3. | Both Statement I and Statement II are incorrect. |
4. | Statement I is correct and Statement II is incorrect. |
A battery consists of a variable number \(n\) of identical cells (having internal resistance \(r\) each) which are connected in series. The terminals of the battery are short-circuited and the current \(I\) is measured. Which of the graphs shows the correct relationship between \(I\) and \(n?\)
1. | 2. | ||
3. | 4. |
Given below two statements:
Statement I: | Kirchhoff’s junction law follows the conservation of charge. |
Statement II: | Kirchhoff’s loop law follows the conservation of energy. |
1. | Both Statement I and Statement II are wrong. |
2. | Statement I is correct but Statement II is wrong. |
3. | Statement I is wrong and Statement II is correct. |
4. | Both Statement I and Statement II are correct. |
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. |