Advertisements
Advertisements
प्रश्न
The current generator Ig' shown in figure, sends a constant current i through the circuit. The wire ab has a length l and mass m and can slide on the smooth, horizontal rails connected to Ig. The entire system lies in a vertical magnetic field B. Find the velocity of the wire as a function of time.
Advertisements
उत्तर
Because current i passes through the sliding wire, the magnetic force on the wire (F) is ilB.
Now,
Acceleration of the sliding wire, `a=(ilB)/m`
Velocity of the sliding wire, v = u + at
∵ u = 0
`therefore v = (ilBt)/m`
APPEARS IN
संबंधित प्रश्न
Depict the behaviour of magnetic field lines in the presence of a diamagnetic material?
Show with the help of a diagram how the force between the two conductors would change when the currents in them flow in the opposite directions?
The motion of copper plate is damped when it is allowed to oscillate between the two poles of a magnet. What is the cause of this damping?
Two identical circular wires P and Q each of radius R and carrying current ‘I’ are kept in perpendicular planes such that they have a common centre as shown in the figure. Find the magnitude and direction of the net magnetic field at the common centre of the two coils.
A moving charge produces
Consider a long, straight wire of cross-sectional area A carrying a current i. Let there be n free electrons per unit volume. An observer places himself on a trolley moving in the direction opposite to the current with a speed \[v = \frac{i}{\text{nAe}}\] and separation from the wire by a distance r. The magnetic field seen by the observer is very nearly
A wire ab of length l, mass m and resistance R slides on a smooth, thick pair of metallic rails joined at the bottom as shown in figure. The plane of the rails makes an angle θ with the horizontal. A vertical magnetic field B exists in the region. If the wire slides on the rails at a constant speed v, show that \[B = \sqrt{\frac{mg R sin\theta}{v l^2 \cos^2 \theta}}\]
Consider the situation shown in figure. The wires P1Q1 and P2Q2 are made to slide on the rails with the same speed 5 cm s−1. Suppose the 19 Ω resistor is disconnected. Find the current through P2Q2 if (a) both the wires move towards right and (b) if P1Q1 moves towards left but P2Q2 moves towards right.
Assertion(A): A proton and an electron, with same momenta, enter in a magnetic field in a direction at right angles to the lines of the force. The radius of the paths followed by them will be same.
Reason (R): Electron has less mass than the proton.
Select the most appropriate answer from the options given below:
A deuteron and an alpha particle having equal kinetic energy enter perpendicular into a magnetic field. Let `r_d` and `r_alpha` be their respective radii of the circular path. The value of `(r_d)/(r_alpha)` is equal to ______.
A circular coil of radius 10 cm is placed in a uniform magnetic field of 3.0 × 10-5 T with its plane perpendicular to the field initially. It is rotated at constant angular speed about an axis along the diameter of coil and perpendicular to magnetic field so that it undergoes half of rotation in 0.2 s. The maximum value of EMF induced (in µV) in the coil will be close to the integer ______.
A thin strip 10 cm long is on a U-shaped wire of negligible resistance and it is connected to a spring of spring constant 0.5 Nm-1. The assembly is kept in a uniform magnetic field of 0.1 T. If the strip is pulled from its equilibrium position and released, the number of oscillations it performs before its amplitude decreases by a factor of e is N. If the mass of the strip is 50 grams, its resistance is 10 Ω, and air drag is negligible, N will be close to ______.
A wire carrying current i has the configuration shown in figure. For the magnetic field to be zero at the centre of the circle, θ must be:
A conductor ABOCD moves along its bisector with a velocity 1 m/s through a perpendicular magnetic field of 1 wb/m2, as shown in figure. If all the four sides are 1 m length each, then the induced emf between A and Din approx is ______V.
An α particle is moving along a circle of radius R with a constant angular velocity ω. Point A lies in the same plane at a distance 2R from the centre. Point A records magnetic field produced by α particle, if the minimum time interval between two successive times at which A records zero magnetic field is 't' the angular speed ω, in terms of t is ______.
Protons and singly ionized atoms of U235 and U238 are passed in turn (which means one after the other and not at the same time) through a velocity selector and then enter a uniform magnetic field. The protons describe semicircles of radius 10 mm. The separation between the ions of U235 and U238 after describing the semicircle is given by ______.
An electron (mass 9 × 10−31 kg and charge 1.6 × 10−19 C) moving with speed c/100 (c = speed of light)is injected into a magnetic field `vecB` of magnitude 9 × 10−4 T perpendicular to its direction of motion. We wish to apply an uniform electric field `vecE` together with the magnetic field so that the electron does not deflect from its path. Then (speed of light c = 3 × 108 m s−1).
