Nuclei — Physics STD 12 Science — Question

A galvanometer of 50 ohm resistance has 25 divisions. A current of 4 × 10^–4 ampere gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of 25 volts, it should be connected with a resistance of

(a) 2500 W as a shunt	(b) 2450 W as a shunt
(c) 2550 W in series	(d) 2450 W in series

If the magnetic flux is expressed in weber, then magnetic induction can be expressed in

(a) Weber/m2

(b) Weber/m

(c) Weber-m

(d) Weber-m2

The energy of a charged capacitor is given by the expression (q = charge on the conductor and C = its capacity)

(a)

(b)

(c) 2qC

(d)

The field due to a long straight wire carrying a current I is proportional to

(a) I

(b)

(c)

(d) 1/I

The de-Broglie wavelength of an electron having 80eV of energy is nearly  (1eV = 1.6 × 10^–19 J,  Mass of electron = 9 × 10^–31kg  Plank’s constant = 6.6 × 10^–34 J-sec)

(a) 140 Å

(b) 0.14 Å

(c) 14 Å

(d) 1.4 Å

The graph shows the variation of magnetic field (B)with distance (r) from a long current carrying wire is-

Focal length of a plane mirror is

(a) Zero

(b) Infinite

(c) Very less

(d) Indefinite

Displacement current goes through the gap between the plates of a capacitor when the charge of the capacitor:

Assertion  :   The surface charge densities of two spherical conductors of different radii are equal. Then the electric field intensities near their surface are also equal.

Reason    : Surface charge density is equal to charge per unit area.

(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 the assertion and reason both are false.

A proton and a neutron combine to give a deuterium nucleus.If mo​ and mp​ be the mass of neutron and proton respectively, then mass of deuterium nucleus is: