Light incident normally on a plane mirror attached to a galvanometer coil retraces backwards as shown in Fig. 9.36. A current in the coilproduces a deflection of `3.5^` of the mirror. What is the displacement of the reflected spot of light on a screen placed 1.5 m away?:

What is the angle of reflection, when a ray of light is incident normally on a plane mirror?

A ray of light strikes a plane mirror at an angle of incidence 45^@ as shown in the figure 9.115. After reflection, the ray of passess through a prism of refractive index 1.5 whose apex angle is 4^@ . Through what angle must the mirror be rotated if the total deviation of hte ray be 90^@ ?

An object is placed 21 cm in front of a concave mirror of radius of curvature 10 cm.A glass slab of thickness 3 cm and refractive index 1.5 is then placed close to the irror in the space between the object and mirror as shown in Fig.2.62.Find the position of the final image formed.You may take the distacne of the near surface of the slab from the mirror to be 1 cm. .

A point source S emitting light of wavelength 600 nm is placed at a very small height h above a flat reflecting surface AB [Fig.6.07].The intensity of the reflected light is 36% of the incident intensity.Interfrerence fringes are observed on a screen placed parallel to the reflecting surface at a very large distance D from it. What is the shape of the interference fringes on the screen?

A circular coil of 20 turns and radius 10 cm is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the coil is 5.0 A, what is the average force on each electron in the coil due to the magnetic field? (The coil is made of copper wire of cross-sectional area 10^-5 m^2 , and the free electron density in copper is given to be about 10^29 m^-3 .)

A small retangular coil ABCD contains 140 turns of wire. The sides AB and BC of the coil are of length 4.5 and 2.8 cm respectively, as shown in the figure The coil is held between the poles of a large magnet so that the coil can rotate about an axis thorugh its centre. The magnet produces a uniform magnetic field of flux density B between its poles. When the current in the coil is 170 mA, the maximum torque produced in the coil is 2.1 xx 10^-3 N m . For the coil in the position for maximum torque, state whether the plane of the coil is parallel to, or normal to , the direction of the magnetic field.

A solenoid 60 cm long and of radius 4.0 cm has 3 layers of windings of 300 turns each. A 2.0 cm long wire of mass 2.5 g lies inside the solenoid (near its centre) normal to its axis, both the wire and the axis of the solenoid are in the horizontal plane. The wire is connected through two leads parallel to the axis of the solenoid to an external battery which supplies a current of 6.0 A in the wire. What value of current (with appropriate sense of circulation) in the windings of the solenoid can support the weight of the wire? g = 9.8 m s^-2 .

The direction of ray of light incident on a concave mirror is shown by PQ while directions in which the ray would travel after reflection is shown by four rays marked 1,2,3 and 4 (Fig. EP 9.8). Which of the four rays correctly shows the direction of reflected ray?

A circular coil of 20 turns and radius 10 cm is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the coil is 5.0 A, what is the total force on the coil, (The coil is made of copper wire of cross-sectional area 10^-5 m^2 , and the free electron density in copper is given to be about 10^29 m^-3 .)