ISRO Scientist or Engineer Mechanical 2014

A spherical balloonis filled with $$3536 \pi$$ cubic meters of helium gas. If a leak in the balloon causes the gas to escape at the rate of $$70 \pi$$ cubic meters per minute, then the rate (in meters per minute) at which the radius of the balloon decreases 50 minutes after the leakage began is

Resistance of a given wire is obtained by measuring the current flowing in it and the voltage difference applied across it. If the percentage errors in the measurement of the current and the voltage difference are 3% each, then error in the value of resistance of the wire is

A purse contains 4 copper coins and 3 silver coins. A second purse contains 6 copper coins and 4 silver coins. A purse is chosen randomly and a coin is taken out of it. What is the probability that it is a copper coin?

The Grash of number, Gr is defined as:(where g is gravitational acceleration, $$\beta$$ is volumetric thermal expansion coefficient, $$\triangle T$$ is temperature difference, L is characteristic length, $$\mu$$ is the viscosity and v is kinematic viscosity.

The Rayleigh number Ra, is defined as: (where Gr is Grashof Number, Pr is Prandtl Number and Re is Reynold Number)

For two bodies having direct impact, Co-efficient of restitution is given by

A perfect frame is that which satisfies the equation (Assume n = No. Of members and j = No. Of joints)

Tension in the cable supporting a lift of weight ‘W’ and having an acceleration of ‘a’ while going upward is (gis acceleration due to gravity)

A body A of weight 10 Kg with its C.G. 25 cm from the axis of rotation is to be balanced by another body B of weight 5 Kg. The radius at which the C.G. of weight B should be placed is

In case of a horizontal beam loaded under bending, the point of inflexion or contra flexure corresponds to a point on the beam, where