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A boat is moving due east in a region where the earth's magnetic field is 5.0 × 10-5 NA-1 m-1 due north and horizontal. The boat carries a vertical aerial 2 m long. If the speed of the boat is 1.50 ms-1, the magnitude of the induced emf in the wire of aerial is ______.
Concept: undefined >> undefined
A coil having n turns and resistance RΩ is connected with a galvanometer of resistance 4RΩ. This combination is moved in time t seconds from a magnetic field W1 weber to W2 weber. The induced current in the circuit is ______.
Concept: undefined >> undefined
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In a U-tube, the radii of two columns are respectively r1 and r2. When a liquid of density ρ(θ = 0°) is filled in it, a level difference of h is observed on two arms, then the surface tension of the liquid is ______.
Concept: undefined >> undefined
When an air bubble of radius r rises from the bottom to the surface of a lake, its radius becomes `(5r)/4`. Taking the atmospheric pressure to be equal to the 10 m height of the water column, the depth of the lake would approximately be ______.
(ignore the surface tension and the effect of temperature)
Concept: undefined >> undefined
The excess pressure inside a liquid drop is 500 Nm-2. If the radius of the drop is 2 mm, the surface tension of the liquid is x × 10-3 Nm-1. The value of x is ______.
Concept: undefined >> undefined
A parallel beam of light is allowed to fall on a transparent spherical globe of diameter 30cm and refractive index 1.5. The distance from the centre of the globe at which the beam of light can converge is ______ mm.
Concept: undefined >> undefined
The focal length f is related to the radius of curvature r of the spherical convex mirror by ______.
Concept: undefined >> undefined
A bar magnet of length 14 cm is placed in the magnetic meridian with its north pole pointing towards the geographic north pole. A neutral point is obtained at a distance of 18 cm from the center of the magnet. If BH = 0.4 G, the magnetic moment of the magnet is ______. (1 G = 10–4T)
Concept: undefined >> undefined
Car B overtakes car A at a relative speed of 40 ms-1. How fast will the image of car B appear to move in the mirror of focal length 10 cm fitted in car A, when car B is 1.9 m away from car A?
Concept: undefined >> undefined
Two short magnetic dipoles m1 and m2 each having a magnetic moment of 1 Am2 are placed at points O and P respectively. The distance between OP is 1 metre. The torque experienced by the magnetic dipole m2 due to the presence of m1 is ______ × 10-7 Nm.
Concept: undefined >> undefined
When a clock is viewed in a mirror, the needles exhibit a time which appears to be 8:20. Then the actual time will be:
Concept: undefined >> undefined
An upright object is placed at a distance of 40 cm in front of a convergent lens of a focal length of 20 cm. A convergent mirror of focal length 10 cm is placed at a distance of 60 cm on the other side of the lens. The position and size of the final image will be ______.
Concept: undefined >> undefined
Two plane mirrors are inclined at an angle of 40°. The possible number of images of an object placed at point P would be?
Concept: undefined >> undefined
A point object is placed at a distance of 30 cm from a convex mirror of a focal length of 30 cm. What is the separation between the image and the object?
Concept: undefined >> undefined
A convex lens of focal length 15 cm is placed coaxially in front of a convex mirror. The lens is 5 cm from the pole of the mirror. When an object is placed on the axis at a distance of 20 cm from the lens, it is found that the image coincides with the object. Calculate the radius of curvature of the mirror - (consider all-optical event):
Concept: undefined >> undefined
The electric field in a region is given by `vec"E"` = (Ax + B) `hat"i"`, where E is in NC-1 and x is in metres. The values of constants are A = 20 SI unit and B = 10 SI unit. If the potential at x = 1 is V1 and that at x = -5 is V2, then V1 - V2 is ______.
Concept: undefined >> undefined
A bar magnet having a magnetic moment of 2.0 × 105 JT-1, is placed along the direction of uniform magnetic field of magnitude B = 14 × 10-5 T. The work done in rotating the magnet slowly through 60° from the direction of field is ______.
Concept: undefined >> undefined
A bar magnet of length 6 cm has a magnetic moment of 4JT-1 Find the strength of magnetic field at a distance of 200 cm from the centre of the magnet along its equatorial line.
Concept: undefined >> undefined
The graph of ln `("R"/"R"_0)` versus ln A (R = radius of a nucleus and A = its mass number) is ______.
Concept: undefined >> undefined
An RC Circuit as shown in the figure is driven by a AC source generating a square wave. The output wave pattern monitored by CRO would look close to:
Concept: undefined >> undefined
