Electric Charges and Fields — Physics STD 12 Science — Question

Which of the following is/ are true for "magnetic lines of force around a bar magnet"?

If the apertature of a telescope is decreased the resolving power will:

The nature of binding for a crystal with alternate and evenly spaced positive and negative ions is(a) Covalent(b) Metallic(c) Dipolar(d) Ionic

Which of the following is a fusion reaction?

Assertion :  If an electron is not deflected while passing through a certain region of space, then only possibility is that there is no magnetic region.
Reason    : Force is directly proportional to the magnetic field applied.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If assertion is false but reason is true.

In LCR series AC circuit.

Angle between equipotential surface and lines of force is (a) Zero(b) 180° (c) 90°(d) 45°

A point object O is placed on the principal axis of a convex lens of focal length 20 cm at a distance of 40 cm to the left of it. The diameter of the lens is 10 cm. If the eye is placed 60 cm to the right of the lens at a distance h below the principal axis, then the maximum value of h to see the image will be(a) 0 (b) 5 cm(c) 2.5 cm(d) 10 cm

To convert mechanical energy into electrical energy, one can use: