InterviewSolution
Saved Bookmarks
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. |
A paramagnetic sample shows a net magnetisation of `8Am^-1` when placed in an external magnetic field of `0*6T` at a temperature of `4K`. When the same sample is placed in an external magnetic field of `0*2T` at a temperature of `16K`, the magnetisation will beA. `(32)/(3)Am^(-1)`B. `(2)/(3)Am^(-1)`C. `6Am^(-1)`D. `2.4Am^(-1)` |
|
Answer» Correct Answer - B |
|
| 2. |
A charged particle with velocity `hatv=xhati+yhatj` moves in a magnetic field `vecB=yhati+xhatj`. The force acting on the particle has magnitude F. Which one of the following statements is are correct?A. No force will act on particle, if x=yB. `Fprop(x^(2)-y^(2))`if xgtyC. The force will act along z-axis, if xgt yD. The force will act along y-axis, if ygt x |
|
Answer» Correct Answer - a,b,c |
|
| 3. |
A charged particle moves in a uniform magnetic field `B=(2hati-3hatj)` TA. if velocity of the particles is `(6hatK)m//s`, particle moves in a circleB. if velocity of the particle is `(-4hati+6hatj)m//s`, particle moves in a straight meC. if velocity of the particle is `(hati+2hatj)m//s`, particle moves in a helical pathD. In all the above three cases speed of the particle remains unchanged |
|
Answer» Correct Answer - all |
|
| 4. |
A particle of charge q and mass m starts moving from the origin under the action of an electric field `vec E = E_0 hat i and vec B = B_0 hat i` with a velocity `vec v = v_0 hat j`. The speed of the particle will become `2v_0` after a time.A. `t= (2mv_(0))/(qE)`B. `t= (2Bq)/(mv_(0))`C. `t= (sqrt3Bq)/(mv_(0))`D. `t= (sqrt3mv_(0))/(qE)` |
|
Answer» Correct Answer - D |
|
| 5. |
A charged particle of unit mass and unit charge moves with velocity `vecv=(8hati+6hatj)ms^-1` in magnetic field of `vecB=2hatkT`. Choose the correct alternative (s).A. the path of the particle may be `x^(2)+y^(2)-4x-21=0`B. the path of the particle may be `x^(2)+y^(2)=25`C. the path of the particle may be `y^(2)+z^(2)=25`D. the time period of the particle will be 3.14 s |
|
Answer» Correct Answer - a,b,d |
|
| 6. |
An ammeter reads upto 1 ampere. Its internal resistance is 0.81 ohm. To increase the range to 10 A the value of the required shunt isA. `0*03Omega`B. `0*3Omega`C. `0*9Omega`D. `0*09Omega` |
| Answer» Correct Answer - D | |
| 7. |
Two identical particles having the same mass m and charges +q and -q separated by a distance d enter a uniform magnetic field B directed perpendicular to paper inwards with speeds `v_1 and v_2` as shown in Fig. 1.139. The particles will not collide if A. `dgt(m)/(Bq)(V_(1)-V_(2))`B. `dlt(m)/(Bq)(V_(1)-V_(2))`C. `dgt(2m)/(Bq)(V_(1)-V_(2))`D. `V_(1)=V_(2)` |
|
Answer» Correct Answer - C |
|
| 8. |
Let current `i=2A` be flowing in each part of a wire frame as shown in Fig. 1.138. The frame is a combination of two equilateral triangles ACD and CDE of side 1 m. It is placed in uniform magnetic field ` B= 4 T` acting perpendicular to the plane of frame. The magnitude of magnetic force acting on the frame is The pithc of the helical path followed by the particle is p. The radius of the helix will beA. 24 NB. zeroC. 16 ND. 8 N |
|
Answer» Correct Answer - A |
|
| 9. |
The CGS unit of magnetising intensity is 1 oersted, where 1 oersted =A. `80Am`B. `80Am^-1`C. `80A^-1m`D. `80A^-1m^-1` |
| Answer» Correct Answer - B | |
| 10. |
A particle of specific charge (charge/mass) `alpha` starts moving from the origin under the action of an electric field `oversetrarrE = E_(0)hati` and magnetic field `oversetrarrB = B_(0)hatk` Its velocity at `(x_(0),y_(0).0)` is `(4hati +3hatj)` The value of `x_(0)` is .A. `(13)/(2)(alphaE_(0))/(B_(0))`B. `(16alphaB_(0))/(E_(0))`C. `(25)/(2alphaE_(0))`D. `(5alpha)/(2B_(0))` |
|
Answer» Correct Answer - B |
|
| 11. |
Which of the following particles will describe wll experience maximum magnetic force(magnitude) when projected with the same velocity perpendicular to a magnetic field?A. ElectronB. ProtonC. `He^(+)`D. `Li^(++)` |
|
Answer» Correct Answer - D |
|
| 12. |
A point charge is moving in clockwise direction in a circle with constant speed. Consider the magnetic field produced by the charge at a fiexed point P (not at the centre of circle ) on the axis of the circle. Then,A. it is constant in magnitude onlyB. it is a constant in direction onlyC. it is constant in direction and magnitude and magnitude bothD. it is not constant in magnitude and direction both |
|
Answer» Correct Answer - A |
|
| 13. |
A charged particle enters into a uniform magnetic field with velocity `v_(0)` perpendicular to it , the length of magnetic field is `x=sqrt(3)/(2)R`, where `R` is the radius of the circular path of the particle in the field .The magnitude of charge in velocity of the particle when it comes out of the field is |
|
Answer» Correct Answer - 1 |
|
| 14. |
Equal currents `i=1` A are flowing through the wires parallel to y-axis located at `x=+1m, x=+2m, x=+4m` and so on...., etc. but in opposite directions as shown in Fig The magnetic field (in tesla) at origin would be A. `-1.33 xx 10^(-7)hatK`B. `1.33 xx 10^(-7)hatK`C. `2.67 xx 10^(7)hatk`D. `-2.67 xx 10^(7)hatk` |
|
Answer» Correct Answer - B |
|
| 15. |
Magnetic field at the centre of a circualr loop of area A carrying current I is B. What is the magnetic moment of this loop?A. `(BA^(2))/(mu_(0)pi)`B. `(BA)/(mu_(0))sqrt(A)`C. `(BAsqrt(A))/(mu_(0)pi)`D. `(2BA)/(mu_(0))sqrt((A)/(pi))` |
|
Answer» Correct Answer - C |
|
| 16. |
A positive charge particle of mass m and charge q is projected with velocity v as shown in Fig. If radius of curvature of charge particle in magnetic field region is greater than d, then find the time spent by the charge particle in magnetic field. A. `(m)/(2qB)`B. `(2m)/(qB)sin^(-1)((d)/(R))`C. `(m)/(qB)`D. `(m)/(qB)sin^(-1)((2d)/(R))` |
|
Answer» Correct Answer - b |
|
| 17. |
A particle of specific charge `q//m = (pi) C//kg` is projected from the origin towards positive x-axis with a velocity of `10 m//s` in a uniform magnetic field `vec(B) = -2 hat K` Tesla. The velocity `vec V` of the particle after time `t =1//6` s will beA. `(5hati+5sqrt3hatj)m//s`B. `10hatJm//s`C. `(5sqrt3hati-5hatj)m//s`D. `-10hatjm//s` |
|
Answer» Correct Answer - a |
|
| 18. |
A positive charge is moving towards an observer. The direction of magnetic induction lines isA. clockwiseB. anticlockwiseC. rightD. left |
| Answer» Correct Answer - B | |
| 19. |
If a long hollow copper pipe carriers a direct current, the magnetic field associated with the current will be:A. only outside the wireB. only inside the wireC. both inside and outside the wireD. neither inside nor outside the wire |
| Answer» Correct Answer - A | |
| 20. |
A conducting circular loop of radius r carries a constant current i. It is placed in a uniform magnetic field B such that B is perpendicular to the plane of loop. What is the magnetic force acting on the loop?A. `irB_(0)`B. `2piirB_(0)`C. zeroD. `piirB_(0)` |
|
Answer» Correct Answer - c |
|
| 21. |
The wire shown in figure carries a current of `10A`. Determine the magnitude of the magnetic field at the centre O. Given radius of the bent coil is `3cm`. A. `1*57xx10^-3T`B. `1*57xx10^-4T`C. `3*14xx10^-3T`D. `3*14xx10^-4T` |
| Answer» Correct Answer - B | |
| 22. |
A circular coil of n turns and radius r carries a current I. The magnetic field at the center isA. `(mu_0nI)/(r)`B. `(mu_0nI)/(2r)`C. `(2mu_0nI)/(r)`D. `(mu_0nI)/(4r)` |
| Answer» Correct Answer - B | |
| 23. |
A rectangular coil of turns `500` and area `2cmxx1cm` carries `100mA` current. It is suspended in a uniform magnetic field of `10^-3T`, so that its plane makes an angle `60^@` with it. The torque on the coil in N-m isA. `5xx10^-2`B. `5xx10^-3`C. `5xx10^-4`D. `5xx10^-6` |
| Answer» Correct Answer - D | |
| 24. |
A circular coil having mass m is kept above ground (x-z plane) at some height. The coil carries i in the direction shown in Fig. 1.143. In which direction a uniform magnetic field `vec B` be applied so that the magnetic force balances the weight of the coil? A. positive x-directionB. negative x-directionC. positive z-directionD. None of these |
|
Answer» Correct Answer - D |
|
| 25. |
A circular coil of n turns and radius r carries a current I. The magnetic field at the centre isA. `(mu_(0)i)/(2R)`B. `(i)/(2c^(2)epsilon_(0)R)`C. `(mu_(0)i)/(2piR)`D. `(ic^(2))/(2epsilon_(0)R)` |
|
Answer» Correct Answer - a,b |
|
| 26. |
In Fig. a coil of single turn is wound on a sphere of radius r and mass m. The plane of the coil is parallel to the inclined plane and lies in the equatorial plane of the sphere. If the sphere is in rotational equilibrium, the value of B is [Current in the coil is i] A. `(mg cos theta)/(pii R)`B. `(mg)/(pi iR)`C. `(mg tan theta )/(pi i R)`D. `(mgsin theta )/(pi i R)` |
|
Answer» Correct Answer - B |
|
| 27. |
A 100 turn closely wound circular coil of radius `10cm` carries a current of `3*2A`. (i) What is the field at the centre of the coil? (ii) What is the magnetic moment of this arrangement? The coil is placed in a vertical plane and is free to rotate about a horizontal axis which coincides with its diameter. A uniform magnetic field of `2T` in the horizontal direction exists such that initially the axis of the coil is in the direction of the field. The coil rotates through an angle of `90^@` under the influence of the magnetic field. (iii) What are the magnitudes of the torques on the coil in the initial and final positions? (iv) What is the angular speed acquired by the coil when it has rotated by `90^@`? The moment of inertia of the coil is `0*1kgm^2`.A. `2xx10T`B. `2xx10^(-3)`TC. `2xx10^(-6)` TD. `2xx10^(-9)`T |
|
Answer» Correct Answer - b |
|
| 28. |
A circular current carrying loop is placed in x-y plane as shown in figure. A uniform magnetic field `B=B_(0)hatK` is present in the region. Match the following. |
|
Answer» Correct Answer - (A) R,(B)P,(C)T,(D)S |
|
| 29. |
Equal current I flows in two segments of a circular loop in the direction shown in figure. Radius of loop is R. What is the magnitude of magnetic field induciton at the centre of the loop? A. zeroB. `((pi- theta)/(pi)(muoi)/(2a))`C. `((2pi- theat)/(pi)) (muoi)/(2a)`D. `((theta)/(2pi))(muoi)/(2a)` |
|
Answer» Correct Answer - C |
|
| 30. |
For a paramagnetic substanceA. `chi_mpropT`B. `chi_m=T^2`C. `chi_m=T^0`D. `chi_m=propT^-1` |
| Answer» Correct Answer - D | |
| 31. |
For a paramagnetic substanceA. `mu_r=1`B. `mu_r=0`C. `mu_rgt1`D. `mu_r=i nfi nity` |
| Answer» Correct Answer - C | |
| 32. |
The magnetic susceptibility of a superconductor isA. `chi_m=1`B. `chi_m=-1`C. `chi_m=0`D. `chi_m=oo` |
| Answer» Correct Answer - B | |
| 33. |
Which of the following statement(s) `is//are` correct ?A. Units of magnetic field B can be written as `(N)/(A-m)`B. Units of magnetic permeability `mu_(0)` can be wirtten as` (N)/(A^(2))`C. Units of magnetic flux `phi` can be written as `(N)/(A-m^(2))`D. Units of magnetic flux can be `(N-m^(2))/(A)` |
|
Answer» Correct Answer - a,b |
|
| 34. |
For the path of a charged particle math the following. |
|
Answer» Correct Answer - (A) P,Q,(B)P,R,S,(C)P,S |
|
| 35. |
A nonconducing disc of radius R is rotaing about axis passing through its cente and perpendicual its plance with an agular velocity `omega` . The magnt moment of this disc is .A. `(1)/(4)qomegaR^(2)`B. `(1)/(2)qomegaR`C. `qomegaR`D. `(1)/(2)qomegaR^(2)` |
|
Answer» Correct Answer - A |
|
| 36. |
In a region where both non-zero uniform electric field and magnetic field coexist, the path of a charged particleA. can not be a circleB. may be a circleC. may be a straight lineD. may be a helix |
|
Answer» Correct Answer - a,c,b |
|
| 37. |
A uniformly charged disc of radius r and having charge q rotates with constant angular velocity `omega`. The magnetic dipole moment of this disc is `(1)/(n)qomegar^(2)`. Find the value of n. |
|
Answer» Correct Answer - 4 |
|
| 38. |
In a region, magnetic field along X-axis changes with time according to the given garph. A charged particle of mass 1 kg and charge 1C located at origin starts moving with initial velocity `((2)/(pi)hati+2sqrt3hatj)m//s`. Completes one revolution in `T_(0)` time. Find the displacement (in m) of particle at time `(5T_(0))/(4). |
|
Answer» Correct Answer - 7 |
|
| 39. |
The structural formula of the ore called natural magnet isA. `FeO_2`B. `Fe_3O_4`C. `FeO_3`D. `Fe_2O_4` |
| Answer» Correct Answer - B | |
| 40. |
When distance between two given magnetic poles is halved, force between them becoems k times, where `k=`A. `1`B. `2`C. `4`D. `1//4` |
| Answer» Correct Answer - D | |
| 41. |
In the shown arrangement magentic field at P is : A. zeroB. `(mu_(0)l)/(2sqrt(2pia))`C. `(mu_(0)l)/(sqrt(2pia))`D. `(mu_(0)l)/(4sqrt(2pia))` |
|
Answer» Correct Answer - D |
|
| 42. |
A charge q is unifomly distrybuted over a nonconducting ring of radius R. The ring is rotated about an axis passing through its centre and perpendicular to the plane of the ring with frequency f. The ratio of electric potential to the magnetic field at the centre of the ring depends on.A. `q,f, and R`B. `q and f only `C. `f and R `D. `f` |
|
Answer» Correct Answer - D |
|
| 43. |
Torque acting on a magnet held at angle `theta` with a magnetic field is maximum, where `theta=`A. `0^@`B. `90^@`C. `360^@`D. `90^@` |
| Answer» Correct Answer - D | |
| 44. |
What is not true about poles of a magnet?A. poles exist always in pairsB. poles of a magnet are always unlikeC. poles of a magnet are of equal strengthD. poles are situated a little outwards from the geometrical ends of magnet |
| Answer» Correct Answer - D | |
| 45. |
A long wire carrying a current `i=2A` is bent at right angles . The magnetic field lying on a perpendicular normal to the plane of the wire draw through the point of bending at distance 1 m form it is ………….Tesla.A. `2 xx 10^(-7)`B. `4sqrt(2)xx 10^(-7)`C. `sqrt(2)xx 10^(-7)`D. `2sqrt(2)xx 10^(-7)` |
|
Answer» Correct Answer - D |
|
| 46. |
A magnetic needle is kept in a non uniform magnetic field . It experiencesA. a force and a torqueB. a force but not a troqueC. a torque but not a forceD. neither a force nor a torque |
|
Answer» Correct Answer - A |
|
| 47. |
In the figure shown a current `I_(1)` is established in the long straight wire AB. Another wire CD carrying currrent `I_(2)` is placed in the plane of the paper. The line joining the ends of this wire is perpendicular to the wire AB. The resultant force on the wire CD is : A. zeroB. towards negative x-axisC. towards positive y-axisD. None of the above |
|
Answer» Correct Answer - d |
|
| 48. |
Two identical magnetic dipoles of magnetic moments `1*0Am^2` each are placed at a separation of `2m` with their axes perpendicular to each other. What is the resultant magnetic field at a point midway between the dipoles?A. `5xx10^(-7)T`B. `sqrt5xx10^(-7)T`C. `10^(-7)T`D. `2xx10^(-7)T` |
|
Answer» Correct Answer - b |
|
| 49. |
A current i is uniformly distributed over the cross section of a long hollow cylinderical wire of inner radius `R_1` and outer radius `R_2`. Magnetic field B varies with distance r form the axis of the cylinder isA. |
|
Answer» Correct Answer - A |
|
| 50. |
The correct value of Bohr magneton isA. `9.27xx10^(-24)Am^2`B. `9.27xx10^(24)Am^2`C. `9.27xx10^(-24)Am^-2`D. `9.27xx10^(24)Am^-2` |
| Answer» Correct Answer - A | |