Alternating Current — Physics STD 12 Science — Question

Which of the following statements is not correct according to Rutherford model?

Two identical coaxial circular loops carry current i each circulating in the clockwise direction. If the loops are approaching each other, then              (a) Current in each loop increases(b) Current in each loop remains the same(c) Current in each loop decreases(d) Current in one-loop increases and in the other it decreases

A current passes through a wire of nonuniform crosssection.
Which of the following quantities are independent of the cross-section?

The X-ray beam emerging from an X-ray tube:

1. Is monochromatic.
2. Has all wavelengths smaller than a certain maximum wavelength.
3. Has all wavelengths greater than a certain minimum wavelength.
4. Has all wavelengths lying between a minimum and a maximum wavelength.

The capacitive reactance in an AC circuit is.

Which of the following statements are true regarding Bohr's model of hydrogen atom
(I)  Orbiting speed of electron decreases as it shifts to  discrete orbits away from the nucleus
(II)  Radii of allowed orbits of electron are proportional to the principal quantum number
(III) Frequency with which electrons orbits around the nucleus in discrete orbits is inversely proportional to the principal quantum number
(IV)  Binding force with which the electron is bound to the nucleus increases as it shifts to outer orbits Select correct answer using the codes given below
Codes :(a) I and III(b) II and IV(c) I, II and III(d) II, III and IV

If 96500 coulombs of electricity liberates one gram equivalent of any substance, the time taken for a current of 0.15 amperes to deposite  20mg of copper from a solution of copper sulphate is (Chemical equivalent of copper = 32)(a) 5 min 20 sec(b) 6 min 42 sec(c) 4 min 40 sec(d) 5 min 50 sec