11.

A ball falling freely from a height of 4.9 m/s hits a horizontal surface. If e = ¾, then the ball will hit the surface second time after:

• 0.5 s

• 1.5 s

• 3.5 s

• 3.4 s

The distance between the sun and the earth be r then the angular momentum of the earth around the sun is proportional to :

• $\sqrt{\mathrm{r}}$

• ${\mathrm{r}}^{3/2}$

• r

• none of these

Hailstone at 0°C falls from a height of 1 km on an insulating surface converting the whole of its kinetic energy into heat. What part of it will melt? (g = 10 m/s²)

• 1/33

• 1/8

• $\frac{1}{3} \times {10}^{-4}$

• All of it will melt

If an error in measurement of radius of a sphere is 1%, what will be the error in the measurement of volume?

• 1 %

• 1.3 %

• 3 %

• 10 %

The length of the second's pendulum is 1 m on earth. If the mass and diameter of a planet are doubled than that of earth. Then its length becomes

• 1 m

• 2 m

• 0.5 m

• 4 m

A coin is dropped in a lift. It takes time t₁ to reach the floor when the lift is stationary. It takes times t₂ when the lift is moving up with constant acceleration. Then:

• t₁ > t₂

• t₂ > t₁

• t₁ = t₂

• t₁ >> t₂

Calculate the amount of heat (in calories) required to convert 5g of ice at 0°C to steam at 100°C

• 3100

• 3200

• 3600

• 4200

A transverse wave is expressed as y = y₀ sin2πfy. For what value of λ, maximum particle velocity is equal to 4 times the wave velocity?

• ${\mathrm{y}}_0\frac{\mathrm{\pi }}{2}$

• $2y_0\mathrm{\pi }$

• $y_0\mathrm{\pi }$

• $\frac{{\mathrm{y}}_0\mathrm{\pi }}{4}$

50 tuning forks are arranged in increasing order of their frequencies such that each gives 4 beats/s with its previous tuning fork. If the frequency of the last fork is octave of the first, then the frequency of the first tuning fork is:

• 200 Hz

• 204 Hz

• 196 Hz

• none of these

The graph between velocity and displacement of a particle, executing SHM is:

• a straight line

• a parabola

• a hyperbola

• an ellipse