Ray Optics and Optical Instruments — Physics STD 12 Science — Question

Which of the following statement is not correct about two parallel conductors carrying equal currents in the same direction?

If an element X has mass number and number of proton 8 then identify element X :

To convert a galvanometer into a voltmeter, one should connect a

(a) High resistance in series with galvanometer

(b) Low resistance in series with galvanometer

(c) High resistance in parallel with galvanometer

(d) Low resistance in parallel with galvanometer

 characteristic X-ray refers to the transition

(a) n = 2to n = 1

(b) n = 3 to n = 2

(c) n = 3  to n = 1

(d) n = 4 to n = 2

For making standard resistance, wire of following material is used:

The basic magnetization curve for a ferromagnetic material is shown in figure. Then, the value of relative permeability is highest for the point

(a) P

(b) Q

(c) R

(d) S

A parallel plate capacitor is charged to a certain voltage. Now, if the dielectric material (with dielectric constant k) is removed then the

An engine uses 30A of current. The resistance offered is 15 ohms. Calculate the power consumed by the engine in horse power.

A proton, a deuteron and an α particle are accelerated through same potential difference and then they enter in a normal uniform magnetic field, the ratio of their kinetic energies will be:

A radioactive sample of U²³⁸ decay to Pb through a process for which half life is 4.5 × 10⁹ years. The ratio of number of nuclei of Pb to U²³⁸ after a time  of 1.5 × 10⁹ years (given 2^1/3 = 1.26)

(a) 0.12

(b) 0.26

(c) 1.2

(d) 0.37