Magnetism — Physics STD 12 Science — Question

How much kinetic energy will be gained by an α - particle in going from a point at 70 V  to another point at 50 V(a) 40 eV (b) 40 keV (c) 40 MeV (d) 0 eV  

In Young’s double slit experiment the amplitudes of two sources are 3a and a respectively. The ratio of intensities of bright and dark fringes will be (a) 3 : 1   (b) 4 : 1(c) 2 : 1    (d)  9 : 1

The chemical equivalent of copper and zinc are 32 and 108 respectively. When copper and silver voltameter are connected in series and electric current is passed through for sometimes, 1.6 g of copper is deposited. Then, the mass of silver deposited will be(a) 3.5 g  (b) 2.8 g(c) 5.4 g  (d) None of these

A photo cell is receiving light from a source placed at a distance of 1 m. If the same source is to be placed at a distance of 2 m, then the ejected electron(a) Moves with one-fourth energy as that of the initial energy(b) Moves with one-fourth of momentum as that of the initial momentum(c) Will be half in number(d) Will be one-fourth in number

A point charge is brought in an electric field. The electric field at a nearby point.

The turn ratio of a transformers is given as 2 : 3. If the current through the primary coil is 3 A, thus calculate the current through load resistance(a) 1 A(b) 4.5 A(c) 2 A(d) 1. 5 A

If two soap bubbles of different radii are connected by a tube:

1. Air flows from bigger bubble to the smaller bubble till the sizes become equal.
2. Air flows from bigger bubble to the smaller bubble till the sizes are interchanged.
3. Air flows from the smaller bubble to the bigger.
4. There lis no flow of air.

A wire of resistance R is divided in 10 equal parts. These parts are connected in parallel, the equivalent resistance of such connection will be (a) 0.01 R(b) 0.1 R(c) 10 R   (d) 100 R