The current in a coil varies with time t as . If the inductance of coil be 10 mH, the value of induced e.m.f. at \(t=2~\mathrm{s}\) will be:
1. \(0.14~\mathrm{V}\)
2. \(0.12~\mathrm{V}\)
3. \(0.11~\mathrm{V}\)
4. \(0.13~\mathrm{V}\)
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
A coil having an area is placed in a magnetic field which changes from in time interval t. The average EMF induced in the coil will be:
1.
2.
3.
4.
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
An electric potential difference will be induced between the ends of the conductor shown in the diagram when the conductor moves in the direction of:
1. P
2. Q
3. L
4. M
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
The number of turns in a coil of wire of fixed radius & length is 600 and its self-inductance is 108 mH. The self-inductance of a coil of 500 turns will be:
1. 74 mH
2. 75 mH
3. 76 mH
4. 77 mH
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
An aeroplane in which the distance between the tips of wings is 50 m is flying horizontally with a speed of 360 km/hr over a place where the vertical component of earth magnetic field is . The potential difference between the tips of wings would be:
1. | 0.1 V | 2. | 1.0 V |
3. | 0.2 V | 4. | 0.01 V |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
A magnetic rod is inside a coil of wire which is connected to an ammeter. If the rod is stationary, which of the following statements is true?
1. | The rod induces a small current. |
2. | The rod loses its magnetic field. |
3. | There is no induced current. |
4. | None of these. |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
A coil of resistance 20 and inductance 5 H has been connected to a 200 V battery. The maximum energy stored in the coil is:
1. | 250 J | 2. | 125 J |
3. | 500 J | 4. | 100 J |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
An aluminium ring B faces an electromagnet A. If the current I through A can be altered, then:
1. | whether I increases or decreases, B will not experience any force. |
2. | if I decreases, A will repel B. |
3. | if I increases, A will attract B. |
4. | if I increases, A will repel B. |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
In the figure magnetic energy stored in the coil is:
1. | Zero | 2. | Infinite |
3. | 25 joules | 4. | None of the above |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
Consider the situation shown in the figure. The wire AB is sliding on the fixed rails with a constant velocity. If the wire AB is replaced by semicircular wire, the magnitude of the induced current will:
1. | increase. |
2. | remain the same. |
3. | decrease. |
4. | increase or decrease depending on whether the semicircle bulges towards the resistance or away from it. |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.