NEET (NTA)-National Eligibility cum Entrance Test (Medical) Physics: Questions 456 - 459 of 2142
Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 2142 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. View Sample Explanation or View Features.
Rs. 550.00 or
Question number: 456
» Current Electricity » Resistances of Different Materials
Question
Two wires of same material have length L and 2L and cross-sectional areas 4A and A respectively. The ratio of their specific resistance would be
Choices
| Choice (4) | Response | |
|---|---|---|
| a. | 1: 2 |
|
| b. | 1: 8 |
|
| c. | 1: 1 |
|
| d. | 8: 1 |
|
Question number: 457
» Current Electricity » Potentiometer
Question
In a potentiometer experiment two cells of emf E1 and E 2 are used in series and in conjunction and the balancing length is found to be 58 cm of the wire. If the polarity of E 2 is reversed, then the balancing length becomes 29 cm.
The ratio of the emf of the two cells is
Choices
| Choice (4) | Response | |
|---|---|---|
| a. | 4: 1 |
|
| b. | 1: 1 |
|
| c. | 2: 1 |
|
| d. | 3: 1 |
|
Question number: 458
» Current Electricity » Series and Parallel Combinations of Resistors
Question
An electric kettle has two heating coils. When one of the coils is switched on, the water begins to boil in 6 minutes. When the other is switched on, the boiling begins in 8 minutes. The time when the boiling begins if both coils are switched on simultaneously is (i) in series (ii) in parallel. (Specific heat of the water is 4.2 joules/gram 0 C)
Select the correct answers and mark it according to the following codes:
- 14 min in series
- 3.43 min in parallel
- 3.43 min in series
- 14 min in parallel
Choices
| Choice (4) | Response | |
|---|---|---|
| a. | 2 and 4 |
|
| b. | 1 and 3 |
|
| c. | 1, 2 and 3 |
|
| d. | 1 and 2 |
|
Question number: 459
» Current Electricity » Electric Cell and Its Internal Resistance
Question
To get the maximum current from a parallel combination of n identical cells each of internal resistance r in an external resistance R,
Choices
| Choice (4) | Response | |
|---|---|---|
| a. | R > > r |
|
| b. | R < < r |
|
| c. | R > r |
|
| d. | R = r |
|