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 |
1. | \(5\) | 2. | \(10\) |
3. | \(15\) | 4. | \(20\) |
The current in a coil varies with time \(t\) as \(I= 3 t^{2} +2t\). If the inductance of coil be \(10\) mH, the value of induced emf at \(t=2~\text{s}\) will be:
1. \(0.14~\text{V}\)
2. \(0.12~\text{V}\)
3. \(0.11~\text{V}\)
4. \(0.13~\text{V}\)
1. | \(0.04\) V | 2. | \(0.4\) V |
3. | \(4\) V | 4. | \(0.004\) V |
The network shown in figure is a part of a complete circuit. If at a certain instant, the current \(i\) is \(10\) A and is increasing at the rate of \(4\times 10^{3}\) A/sec, then \(V_A-V_B\) is:
1. | \(6\) V | 2. | \(-6\) V |
3. | \(10\) V | 4. | \(-10\) V |
A rod \(AB\) of length \(l\) is moving with constant speed \(v\) in a uniform magnetic field on a conducting \(U\)-shaped wire as shown. If the rate of loss of heat energy across resistance \(R\) is \(Q,\) then the force needed parallel to velocity to keep rod moving with constant speed \(v\) is:
1. \(Qv\)
2. \(\dfrac{Q}{v}\)
3. \(\dfrac{Q^2}{v}\)
4. \(Q^2v\)
A coil is wound of a frame of rectangular cross-section. If the linear dimensions of the frame are doubled and the number of turns per unit length of the coil remains the same, then the self inductance increases by a factor of:
1. | \(6\) | 2. | \(12\) |
3. | \(8\) | 4. | \(16\) |
I: | A small magnet takes a longer time in falling into a hollow metallic tube without touching the wall. |
II: | There is an opposition to motion due to the production of eddy currents in a metallic tube. |
Choose the correct option for the above statements:
1. | Both I and II are True and II is the correct explanation for I. |
2. | Both I and II are True and II is not the correct explanation for I. |
3. | I is True but II is False. |
4. | I is False but II is True. |
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. \(M\)