Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

The inability of a lens to bring all the rays coming from a point object to focus at one single point is called:

A liquid can easily change its shape but a solid can not because.

1. The density of a liquid is smaller than that of a solid.
2. The forces between the molecules is stronger in solid than in liquids.
3. The atoms combine to form bigger molecules in a solid.
4. The average separation between the molecules is larger in solids.

The resistance of a coil is 4.2 Ω at 100 ^oC and the temperature coefficient of resistance of its material is 0.004/^o C.  Its resistance at 0^o C is

(a) 6.5 Ω

(b) 5 Ω

(c) 3 Ω

(d) 4 Ω

Out of the following sources which gives best monochromatic light ?

When   electrons are removed from a neutral metal sphere, the charge on the sphere becomes

(a) 16 μC

(b) -16 μC

(c) 32 μC

(d) -32 μC

Two resistors R and 2R are connected in series in an electric circuit. The thermal energy developed in R and 2R are in the ratio:

The reactance of a circuit is zero. It is possible that the circuit contains:

Which of the following phenomena cannot be explained by the Huygens' wave theory?

According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is

(a)

(b)

(c)

(d)

The correct relation is (Where  Horizontal component of earth's magnetic field;  = Vertical component of earth's magnetic field and B  = Total intensity of earth's magnetic field)

(a) B =

(b)

(c) |B| =

(d)