11.

An alpha nucleus of energy $\frac{1}{2} {\mathrm{mv}}^2$ bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to

• v²

• 1/ m

• 1/ν⁴

• 1/ Ze

Diwali rocket is ejecting 50 g of gases/s at a velocity of 400 m/s. The accelerating force on the rocket will be

• 22 dyne

• 20 N

• 20 dyne

• 100 N

The maximum number of possible interference maxima for slit-separation equal to twice the wavelength in Young's double slit experiment is

• infinite

• five

• three

• zero

A particle executes simple harmonic oscillation with an amplitude $\mathrm{\alpha }$ . The period of oscillation is T. The minimum time taken by the particle to travel half of the amplitude from the equilibrium position is

• $\frac{\mathrm{T}}{4}$

• $\frac{\mathrm{T}}{8}$

• $\frac{\mathrm{T}}{12}$

• $\frac{\mathrm{T}}{2}$

An observer moves towards a stationary source of sound, with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency ?

• Zero

• 0.5 %

• 5 %

• 20 %

Which of the following parameters does not characterise the thermodynamic state of matter?

• Temperature

• Pressure

• Work

• Volume

A charged oil drop is suspended in uniform field of 3 x 10⁴ V/m so that it neither falls nor rises. The charge on the drop will be (Take the mass of the charge = 9.9 x 10^-15 kg and g = 10 m/s² )

• 3.3 × 10^-18 C

• 3.2 × 10^-18 C

• 1.6 × 10^-18 C

• 4.8 × 10^-18 C

The work of 146 kJ is performed in order to compress one kilo mole of a gas adiabatically and in this process the temperature of the gas increases by 7°C. The gas is (R= 8.3J mol^-1 K^-1 )

• diatomic

• triatomic

• a mixture of monoatomic and diatomic

• monoatomic

A frame made of metallic wire enclosing a surface area A is covered with a soap film. If the area of the frame of metallic wire is reduced by 50%, the energy of the soap film will be changed by

• 100%

• 75%

• 50%

• 25%

Mercury boils at 367^oC. However, mercury thermometers are made such that they can measure temperature upto 500^oC. This is done by

• maintaining vacuum above mercury column in the stem of the thermometer

• filling nitrogen gas at high pressure above the mercury column

• filling oxygen gas at high pressure above the mercury column

• filling nitrogen gas at low pressure above the mercury column