The breaking stress of a wire depends upon
length of the wire
material of the wire
radius of the wire
shape of the cross-section
The density of a substance at 0°C is 10 g/cc and at 100° C, its density is 9.7 g/cc. The coefficient of linear expansion of the substance is
10-4
102
10-3
102
According to Wein's displacement law
λT = constant
λ/T = constant
λ ∝ ( 1/ T2 )
both (b) and (c)
A black body is at a temperature 300 K. It emits energy at a rate, which is proportional to
300
(300)3
(300)2
(300)4
The latent heat of vapourisation of water is 2240. If the work done in the process of vapourisation of 1 g is 168 J, then increase in internal energy is
2408 J
2072 J
2240 J
1904 J
The velocities of sound at the same temperature in two monoatomic gases of densities ρ1 and ρ2 and ν1 and ν2 respectively. If ρ1 / ρ2 = 4, then the value of ν1/ ν2 is
1/4
2
1/2
4
The property utilized in the manufacture of lead shots is
specific weight of liquid lead
compressibility of liquid lead
specific gravity of liquid lead
surface tension of liquid lead
D.
surface tension of liquid lead
The property utilized in the manufacture of lead shots is surface tension of liquid lead. In this process, molten lead is made to pass through a sieve from a high tower and allowed to fall in water. The molten lead particles, while descending, assume a spherical shape and solidify in this form, before falling into water.
Assertion: Thin films such a soap bubble or a thin layer of oil on water show beautiful colours when illuminated by white light.
Reason: It happens due to the interference of light reflected from upper surface of the thin film.
If both the assertion and reason are true and reason is a correct explanation of assertion.
If both assertion and reason are true but assertion is not a correct explanation of the assertion.
If both the assertion is true but the reason is false.
If both assertion and reason are false.