Infinite number of bodies, each of mass 2 kg are situated on x-axis at distance 1 m, 2 m, 4 m, 8 m respectively from the origin. The resulting gravitational potential due to this system at the origin will be

• − G

• $- \frac{8}{3} \mathrm{G}$

• $- \frac{4}{3} \mathrm{G}$

• − 4 G

A gas is taken through the cycle A → B → C → A, as shown. What is the net work done by the gas ?

• 2000 J

• 1000 J

• Zero

• − 2000 J

The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied ?

• Length = 50 cm, diameter = 0.5 mm

• Length = 100 cm, diameter = 1 mm

• Length = 200 cm, diameter = 2 mm

• Length= 300 cm, diameter= 3 mm

The wettability of a surface by a liquid depends primarily on

• viscosity

• surface tension

• density

• angle of contact between the surface and the liquid

The molar specific heats of an ideal gas at constant pressure and volume are denoted by C_P and C_V respectively. If $\mathrm{\gamma } = \frac{{\mathrm{C}}_{\mathrm{p}}}{{\mathrm{C}}_{\mathrm{V}}}$ and R is the universal gas constant, then C_V is equal to

• $\frac{1 + \mathrm{\gamma }}{1 - \mathrm{\gamma }}$

• $\frac{\mathrm{R}}{\left(\mathrm{\gamma } - 1\right)}$

• $\frac{\left(\mathrm{\gamma } - 1\right)}{\mathrm{R}}$

• γR

A piece of iron is heated in a flame. If first becomes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is possible by using

• Stefan's law

• Wien's displacement law

• Kirchoff's law

• Newton's law of cooling

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its temperature. The ratio of $\frac{{\mathrm{C}}_{\mathrm{p}}}{{\mathrm{C}}_{\mathrm{v}}}$ for the gas is

• $\frac{4}{3}$

• 2

• $\frac{5}{3}$

• $\frac{3}{2}$

18.

In the given (V-T) diagram, what is the relation between pressures p₁ and p₂ ?

           

• p₂ = p₁

• p₂ > p₁

• p₂ < p₁

• Cannot be predicted

The amount of heat energy required to raise the temperature of 1 g of helium at NTP, from T₁K to T₂K is

• $\frac{3}{8} {\mathrm{N}}_{\mathrm{a}}{\mathrm{K}}_{\mathrm{B}}\left({\mathrm{T}}_2 - {\mathrm{T}}_1\right)$

• $\frac{3}{2} {\mathrm{N}}_{\mathrm{a}}{\mathrm{K}}_{\mathrm{B}}\left({\mathrm{T}}_2 - {\mathrm{T}}_1\right)$

• $\frac{3}{4} {\mathrm{N}}_{\mathrm{a}}{\mathrm{K}}_{\mathrm{B}}({\mathrm{T}}_2 - {\mathrm{T}}_1)$

• $\frac{3}{4} {\mathrm{N}}_{\mathrm{a}}{\mathrm{K}}_{\mathrm{B}}\left(\frac{{\mathrm{T}}_2}{{\mathrm{T}}_1}\right)$

A wave travelling in the positive x-direction having displacement along y-direction as 1 m, wavelength 2$\mathrm{\pi }$ m and frequency of $\frac{1}{\mathrm{\pi }}$ Hz is represented by

• y = sin (x − 2t)

• $\mathrm{y} = \sin (2\mathrm{\pi x} - 2\mathrm{\pi t})$

• $y = \sin (10\mathrm{\pi x} - 20\mathrm{\pi t})$

• $\mathrm{y} = \sin (2\mathrm{\pi x} + 2\mathrm{\pi t})$