A cockroach is moving with a velocity v in anticlock direction on the rim of a disc of radius R of mass m The moment of inertia of the disc about the axis is II and it is rotating in clockwise direction with an angular velocity ω. If the cockroach stops, the angular velocity of the disc will be

 

A spring of force constant 800 Nm^-1 has an extension of 5cm. The work done in extending it from 5 cm to 15 cm is

1) 16 J 
2) 8 J 
3) 32 J
4) 24 J

An n-p-n transistor of current gain 80 in common emitter mode gives emitter current equal to 8.1 mA. The base current is

1) 0.1 $$\mu$$A
2) 0.1 mA
3) 0.01 mA
4) 0.01 $$\mu$$A

The specific heats, $$C_P$$ and $$C_V$$ of a gas of diatomic molecules, A, are given (in units of J mol$$^{-1} K^{-1}$$) by 29 and 22, respectively.

1) A has one vibrational mode and B has two
2) Both A and B have a vibrational mode each
3) A is rigid but B has a vibrational mode
4) A has a vibrational mode but B has none

The heart of a man pumps 4000 cc of blood through the arteries per minute at a pressure of 130 Hg. If the density of mercury is 13.6 ×10³ kg/m³, what is the power of heart ? 
1) 1.15 watt  2) 2.30 watt    3) 1.15 hp   4) 0.115 hp 

A body of mass 1kg begins to move under the action of a time dependent force F=(2ti+3t² k)N. What will be power developed by the force

1) (2t²+3t³ ) W
2) (2t²+4t⁴ ) W
3) (2t³+3t⁴ ) W
4) (2t³+3t⁵ ) W 

 The increase in electrostatic potential energy of a dipole of moment p when it is taken from parallel to anti-parallel orientation in an electric field E is

1) 2pE
2) 3pE
3) 4pE
4) 5pE

 Two satellites A and B of the same mass are going around the earth in concentric orbits. The distance of satellite B from earth’s center is twice that of satellite A. What is the ratio of the speed of B to that of A?

1. ½

2. 1/Ö2

The ionigation energy of hydrogen atom is 13.6 eV. The ionigation energy of helium atom would be

1)   27.2 eV
2)   13.6 eV
3)   54.4 eV
4)   6.8 eV

A person climbs up a stalled escalator in 60 s. If standing on the same but escalator running with constant velocity he takes 40 s. How much time is taken by the person to walk up the moving escalator?

1) 37 s  2) 27 s  3) 24 s   4) 45 s