Magnetism And Matter — Physics STD 12 Science — Question

Sodium and copper have work functions 2.3 eV and 4.5 eV respectively. Then the ratio of the wavelengths is nearest to?

A light ray is incident by grazing one of the face of a prism and after refraction ray does not emerge out, what should be the angle of prism while critical angle is C

(a) Equal to 2C

(b) Less than 2C

(c) More than 2C

(d) None of the above

A Daniel cell is balanced on 125 cm length of a potentiometer wire. Now the cell is short-circuited by a resistance 2 ohm and the balance is obtained at 100 cm. The internal resistance of the Daniel cell is

(a) 0.5 ohm

(b) 1.5 ohm

(c) 1.25 ohm

(d) 4/5 ohm

The electric potential (V) inside a uniformly charged. spherical shell depends on distance:

A dip circle is so set that its needle moves freely in the magnetic meridian. In this position, the angle of dip is 40º. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of 30º with the magnetic meridian. In this position, the needle will dip by an angle:

A radioactive sample with a half life of 1 month has the label : “Activity=2 micro curies on 1.8.1991.'' What will be its activity two months later

(a) 1.0 micro curies

(b) 0.5 micro curies

(c) 4 micro curies

(d) 8 micro curies

The possible values of principal quantum number can be:

A sphere is rotating about a diameter:

1. The particles on the surface of the sphere do not have any linear acceleration.
2. The particles on the diameter mentioned above do not have any linear acceleration.
3. Different particles on the surface have different angular speeds.
4. All the particles on the surface have same linear speed.