Electromagnetic Induction — Physics STD 12 Science — Question

Draw a labelled diagram of a refracting telescope. Obtain an expression for its magnifying power. Write two main disadvantages of refracting telescope as compared to reflecting telescope. ### What is meant by telescope? Draw the ray diagram of image formation by a refracting telescope. Briefly describe its working and derive the formula for its magnifying power.

A long, straight wire is fixed horizontally and carries a current of 50.0A. A second wire having linear mass density 1.0 × 10^-4kg/m is placed parallel to and directly above this wire at a separation of 5.0mm. What current should this second wire carry such that the magnetic repulsion can balance its weight?

Define resolving power of a compound microscope. How does the resolving power of a compound microscope change when:

1. Refractive index of medium between the object and objective lens increases.
2. Wavelength of radiation used is increased?

In beta decay, an electron (or a positron) is emitted by a nucleus. Does the remaining atom get oppositely charged?

In a certain region of space, electric field is along the z-direction throughout. The magnitude of electric field is, however, not constant but increases uniformly along the positive z-direction, at the rate of 10⁵ NC^-1 per metre. What are the force and torque experienced by a system having a total dipole moment equal to 10^-7 Cm in the negative z-direction?

A force F₁ acts on a particle so as to accelerate it from rest to a velocity v. The force F₁ is then replaced by F₂ which decelerates it to rest:

1. F₁ must be equal to F₂.
2. F₁ may be equal to F₂.
3. F₁ must be unequal to F₂.
4. None of these.

Find the maximum magnifying power of a compound Microscope having a 25 diopter lens as the objective, a 5 diopter lens as the eyepiece and the separation 30cm between the two lenses. The least distance for clear vision is 25cm.

A rod of length L has a total charge Q distributed uniformly along its length. It is bent in the shape of a semicircle. Find the magnitude of the electric field at the centre of curvature of the semicircle.

Define electric flux. Find the expression for the electric field intensity due to the electric dipole at its axial point. Draw a diagram.