Physics Test 145

A particle of charge q is projected with a momentum It emerges from the magnetic field after deviating through an angle θ = 30°.

Find the potential difference V_a – V_b between the points a and b shown in each part of the figure. 

A bullet of mass m and charge q is fired towards a solid uniformly charged sphere of radius R and total charge +q. If it strikes the surface of sphere with speed u, find the minimum speed u so that it can penetrate through the sphere. (Neglect all resistance forces or friction acting on bullet except electrostatic force):-

As shown in the figure, P and Q are two coaxial conducting loops separated by some distance. When the switch S is closed, a clockwise current l_P flows in P (as seen by E) and an induced current  flows in Q. The switch remains closed for a long time. When S is opened, a current  flows in Q. Then the directions of  and  (as seen by E) are  :-

If the angles of dip at two places are 30º and 45º respectively, then the ratio of horizontal  components of earth's magnetic field at the two places will be :-

A car is fitted with a convex side-view mirror of focal length 20 cm. A second car 2.8 m behind the first car is overtaking the first car at a relative speed of 15 m/s. The speed of the image of the second car as seen in the mirror of the first one is :-

In Young's double slit experiment, if the width of the slits are in the ratio 4 : 9 the ratio of the intensity of maxima to the intensity at minima will be :–

In a Young's double slit experiment, the two slits act as coherent sources of waves of equal amplitude A and wavelength λ. In another experiment with the same arrangement the two slits are made to act as incoherent sources of waves of same amplitude and wavelength. If the intensity at the middle point of the screen in the first case is I₁ and in the second case I₂, then the ratio l₁/l₂ is :-

In the Young’s double slit experiment, the intensity on the screen at a point where path difference is λ is K. What will be the intensity at the point where path difference is λ/4 - 

The above p-v diagram represents the thermodynamic cycle of an engine, operating with an ideal monoatomic gas. The amount of heat, extracted from the source in a single cycle is :