InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
An accumulator battery (storage cell) `B` of emf `epsilon` and internal resistance `r` is being charged from `DC` supply whose terminals are `T_1` and `T_2` .A. Potential difference bertween `T_(1)` and `T_(2)` must be `gt varepsilon`B. `T_(1)` must be positive with respect to `T_(2)`C. in the battery, current flows from the positive to the negative terminal.D. All the above options are incorrect. |
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Answer» Correct Answer - A::B::C |
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| 2. |
Capacitors `C_(1)=1 muF` and `C_(2)=2muF` are separately charged from the same battery. They are allowed to discharge separately through equal resistorsA. The currents in the two discharging circuits at `t=0` is zeroB. The currents in te two discharging circuits at `t=0` are equal but not zero.C. The currents in the two discharging circuits at `t=0` are unequal.D. `C_(1)` loses `50%` of its initial charge sooner than `C_(2)` loses `50%` of its initial charge. |
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Answer» Correct Answer - C::D |
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| 3. |
A milliammeter of range of `10 mA` gives full-scale deflection for a current of `100 mA`, when a shunt of `0.1 Omega` is connected in parallel to it. The coil of the milliammeter has a resistance of.A. `0.9Omega`B. `1 Omega`C. `1.1 Omega`D. `0.11 Omega` |
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Answer» Correct Answer - A |
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| 4. |
A cell drives a current through a circuit. The emf of the cell of equal to the work done in moving unit charge (Choose the incorrect option)A. from the positive to the negative plate of the cellB. from the positive plate, back to the positive plateC. from the negative plate, back to the negative plateD. from any point in the circuit back to the same point |
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Answer» Correct Answer - B::C::D |
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| 5. |
In the network shown below, the equivalent resistance between `A` and `B` is A. `R//2`B. `R`C. `2R`D. `4R` |
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Answer» Correct Answer - A |
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| 6. |
`A` and `B` are two points on a uniform ring of resistance `R` the `/_ASCB=theta`, whre `C` is the centre of the sign. The equivalent reisrtance between `A` and `b`A. `R/(4pi^(2))(2pi-theta)theta`B. `R(I-(theta)/(2pi))`C. `R (theta)/(2pi)`D. `R(2pi-theta)/(4pi)` |
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Answer» Correct Answer - A |
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| 7. |
In the network shown, each resistance is equal to `R`. The equivalent resistance between diagonally opposite corners isA. `R`B. `R//3`C. `2R//3`D. `4R//3` |
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Answer» Correct Answer - C::D |
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| 8. |
In the network shown in figure, the ring has zero resistance. Find the resistance between A and B. A. `2R`B. `4R`C. `7R`D. `10R` |
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Answer» Correct Answer - A |
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| 9. |
The two ends of a uniform conductor are joined to a cell of e.m.f. `E` and some internal resistance. Starting from the midpoint `P` of the conductor, we move in the direction of current and return to `P`. The potential `V` at every point on the path is plotted against the distance covered `(x)`. which of the following graphs best represent the resulting curve ?A. B. C. D. |
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Answer» Correct Answer - B |
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| 10. |
The Wheatstone bridge shown in the above figure is balanced. If the positions of the cell `C` and the galvanometer `G` are now interchanged, `G` will show zero deflectionA. in all casesB. only if all the resistances are qualC. only if `R_(1)=R_(3)` and `R_(2)=R_(4)`D. only if `R_(1)//R_(3)=R_(2)//R_(4)` |
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Answer» Correct Answer - A |
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| 11. |
Six identical wires of resistance `R` each are joined to form a pyramid, as shown in the figure aboveA. The equivalent resistance between any two corners will depend on the choice of cornersB. The equivalent resistance between `A` and `B` is `R//2`C. The equivalent resistance between `D` and `C` is zeroD. If an electric current enters at `A` and flows out at `B`, no current will pass through `DC`. |
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Answer» Correct Answer - B::D |
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| 12. |
When a `500-W` electric and a `500-W` heater operate at their rates voltages, the filament of the bulb reaches a much higher temperature than the filament of the heater. The most important reason for this thatA. their resistances are not equalB. they are made of different materialsC. their dimensions are very differentD. they radiate different powers at different temperatures |
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Answer» Correct Answer - C::D |
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| 13. |
In the circuit shown above, each of the four conductors is of resistance `R`. The potentail difference between `A` and `B` is `V`. The current flowing between `A` and `B` isA. `V/R`B. `(2V)/R`C. `(3V)/R`D. `(4V)/R` |
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Answer» Correct Answer - D |
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| 14. |
When an electric heater is switched on, the current flowing through it ( i ) is plotted against time ( t ). Taking into account the variation of resistance with temperature, which of the following best represents the resulting curveA. B. C. D. |
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Answer» Correct Answer - B |
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| 15. |
Two electric bulbs rated `25 W , 220 V and 100 W , 220 V` are connected in series across a `220 V` voltage source . The `25 W and 100 W` bulbs now draw `P_(1) and P_(2)` powers , respectively.A. `P_(1)=16W`B. `P_(1)=4W`C. `P_(2)=16W`D. `P_(2)=4W` |
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Answer» Correct Answer - A::D |
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| 16. |
An electric bulb rated for 500 watts at 100 volts is used in a circuit having a 200 volts supply. The resistance R that must be put in series with the bulb, so that the bulb delivers 500 watt is ………ohm.A. `10Omega`B. `20 Omega`C. `50 Omega`D. `100 Omegas` |
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Answer» Correct Answer - B |
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| 17. |
The charge flowing through a resistance `R` varies with time `t as Q = at - bt^(2)`. The total heat produced in `R` isA. `(a^(3)R)/(6b)`B. `(a^(3)R)/(3b)`C. `(a^(3)R)/(2b)`D. `(a^(3)R)/b` |
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Answer» Correct Answer - A |
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| 18. |
An ideal cell is connected to a capacitor through a voltmeter. The reading `V` of the voltmeter is plotted agains time. Which of the following best represents the resulting curve?A. B. C. D. |
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Answer» Correct Answer - B |
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| 19. |
A microameter has a resistance of `100 omega` and a full scale range of ` 50 muA`. It can be used as a voltmeter or as a higher range ammeter provides a resistance is added to it . Pick the correct range and resistance combination(s)A. Range `50V`, with a `10-kQ` resistance in seriesB. Range `10V`, with a `(2xx10^(5)-100)-Omega` resistance in seriesC. Range `5mA`, with `1.01-Omega` resistance in parallelD. Range `10mA`, with a `1-Omega` resistance in parallel |
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Answer» Correct Answer - B::C |
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| 20. |
A voltmeter and an ammeter are joined, in series to an ideal cell, giving reading V and A respectively. If a resistance equal to the resistance of the ammeter is now joined in parallel to the ammeter then :A. `V` will not changeB. `V` will increase slightlyC. `A` will become exactly half to its initial valueD. `A` will become slightly more than half of its initial value |
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Answer» Correct Answer - B::D |
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| 21. |
Two identical fuses are rated at `10A`. If they are joinedA. in parallel, the combination acts as a fuse of rating `20A`B. in parallel the combination acts as a fuse of rating `5A`C. in series, the combination acts as a fuse of rating `10A`D. in series, the combination acts as a fuse of rating `20A` |
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Answer» Correct Answer - A::C |
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| 22. |
a capacitor of capacitance `C` is connected to two voltmeter `A` and `B`. `A` is ideal , having infinite resistance, while `B` has resistance `R`. The capcitor is charged and then switch `S` is closed. The reading of `A` and `B` will be equal A. at all timesB. after time `RC`C. after time `RC In 2`D. only after a very long time |
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Answer» Correct Answer - A |
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| 23. |
An ammeter and a voltmeter are joined in sereis to a cell. Their readings are `A` and `V` respectively. If a resistance is now joinding parallel with the voltmeter. ThenA. both `A` and `V` will increaseB. both `A` and `V` will decreaseC. `A` will decrease, `V` will increaseD. `A` will increase, `V` will decrease |
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Answer» Correct Answer - D |
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| 24. |
A capacitor `A` with charge `Q_(0)` is connected through a resistance to another identical capacitor `B`, which has no charge. The charges on `A` and `B` after time `t` are `Q_(A)` and `Q_(B)` respectively, and they are plotted against time `t`. Find the correct curvesA. B. C. D. |
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Answer» Correct Answer - A |
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| 25. |
The capacitor C is initially without charge. X is now joined to Y for a long time, during which `H_1` heat is produced in the resistance R. X is now joined to Z for a long time, during which `H_2` heat is produced in R A. `H_(1)=H_(2)`B. `H_(1)=1/2H_(2)`C. `H_(1)=2H_(2)`D. The maximum energy stored in `C` at any time is `H_(1)` |
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Answer» Correct Answer - A::D |
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| 26. |
A voltmeter of resistance `600 Omega` when connected in turn across resistances `R_(1)` and `R_(2)` gives readings of `V_(1)` and `V_(2)`, respectively. If the battery is ideal, then A. `V_(1)=80V`B. `V_(1)=60V`C. `V_(2)=30V`D. `V_(2)=40V` |
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Answer» Correct Answer - B::C |
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| 27. |
The charge on a capacitor decrease `eta` time in time `t`, when it discharging through a circuit with a time constant` tau`A. `t=eta tau`B. `t= tau In eta`C. `t= tau (In eta-1)`D. `t= tau In (1- 1/(eta))` |
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Answer» Correct Answer - B |
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| 28. |
A parallel- plate capacitor, fileld with a dielectric of dielectric consatnt `k`, is charged to a potential `V_(0)`. It is now disconnected from the cell and the slab is removed. If it now discharges, with time constant `tau`, through a resistance then find time after which the potential difference across it will be `V_(0)` ?A. `ktau`B. `tau In k`C. `tau In (1-1/k)`D. `tau In (k-1)` |
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Answer» Correct Answer - B |
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| 29. |
N identical cells are connected to form a battery. When the terminals of the battery are joined directly (short - circuited), current I flows in the circuit. To obtain the maximum value of I,A. all the cells should be joined in sereisB. all the cells should be joined in parallelC. two rows of `N//2` cells each should be joined in parallelD. `sqrt(N)` rows of `sqrt(N)` cells each should be joined in parallel, given that `sqrt(N)` is an integer |
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Answer» Correct Answer - B |
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| 30. |
n identical cells, each of emf E and internal resistance r, are joined in series to form a closed circuit. Find the potential difference across any one cell.A. zeroB. `varepsilon`C. `(varepsilon)/n`D. `(n-1)/n varepsilon` |
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Answer» Correct Answer - A |
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| 31. |
In the circuit shown in fig. the cell has emf 10V and internal resistance `1 Omega` A. The current through the `3-Omegas` resistor is `1A`.B. The current though the `3-Q` resistor is `0.5A`C. The current through the `4-Omega` resistor is `0.5A`D. The current through the `4-Omega` resistor is `0.25 A` |
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Answer» Correct Answer - A::D |
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| 32. |
A capacitor is charged and then made to discharged through a resistance. The time constant is `tau`. In what time will the potential difference across the capacitor decreases by `10%`?A. `tau In (0.1)`B. `tau In (0.9)`C. `tau In (10//9)`D. `tau In (11//10)` |
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Answer» Correct Answer - C |
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| 33. |
Current flows through a metallic conductor whose area of cross-section increases in the direction of the current. If we move in this direction.A. the current will changeB. the carrier density will changeC. the drift velocity will increaseD. the drift velocity will decrease |
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Answer» Correct Answer - D |
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| 34. |
In the circuit shown in fig. the cell is ideal with emf 15V. Each resistance is of `3Omega.` The potential difference across the capacitor in steady state is A. zeroB. `9V`C. `12V`D. `15V` |
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Answer» Correct Answer - C |
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| 35. |
A straight conductor of uniform cross-section carries a current `I`. Let `s=` specific charge of an electron. The momentum of all the free electrons per unit length of the conductor, due to their drift velocity only, isA. `Is`B. `I//s`C. `sqrt(I//s)`D. `(I//s)^(2)` |
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Answer» Correct Answer - B |
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