A thermally insulated rigid container contains an ideal gas heated by a filament of resistance 100W through a current of 1A for 5 min then change in internal energy is

1) 0 KJ 
2) 10 KJ
3) 20 KJ
4) 30 KJ

 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

A satellite is revolving in a circular orbit at a height ‘$$h$$’ from the earths surface (radius of earth $$R$$; $$h < < R$$). The minimum increase in its orbital velocity required, so that the satellite could escape from the earths gravitational field, is close to : (Neglect the effect of atmosphere.)

1) $$\sqrt{2gR}$$
2) $$\sqrt{gR}$$
3) $$\sqrt{gR/2}$$
4) $$\sqrt{gR}\left(\sqrt{2}-1\right)$$

A massive stone pillar $$20m$$ high and of uniform cross section rests on a rigid base and supports a vertical load of $$5.0\times { 10 }^{ 5 }N$$ at its upper end. If the compressive stress in the pillar is not exceed $$16\times { 10 }^{ 6 }N/m$$, what is the minimum cross-sectional area of the pillar? (Density of the stone$$=2.5\times { 10 }^{ 3 }kg/{ m }^{ 3 }$$ take $$g=10N/kg$$
1) $$0.15{ m }^{ 2 }$$ 2) $$0.25{ m }^{ 2 }$$ 3) $$0.35{ m }^{ 2 }$$ 4) $$0.45{ m }^{ 2 }$$

If minimum voltage in an AM wave was found to be 2V and maximum voltage 10V. The % modulation index 

1) 80%
2) 66.67%
3) 64.25%
4) 76.25%

Let the x - z plane be the boundary between two transparent media. Medium 1 in Z ≥ 0  has a refractive index of Ö2  and medium 2 with z < 0 has a refractive index of  Ö3. A ray of light in medium 1 given by the vector    is incident on the plane of separation. The angle of refraction in medium 2 is

1) 45°
2) 60°
3) 75°
4) 30°

A moving coil Galvanometer of resistance 100W is converted to ammeter by a resistance of 0.1W in the circuit. Galvanometer gives full scale deflection at 100µA. The minimum current in the circuit for maximum deflection is

(1) 100.1 mA      (2) 1000.1 mA

(3) 1.001 mA      (4) 10.01 mA

A ceiling fan rotates about its own axis with some angular velocity. When the fan is switched off, the angular velocity becomes (1/4)th of the original in time ′t′ and ′n′ revolutions are made in that time. The number of revolutions made by the fan during the time interval between switch off and rest are (Angular retardation is uniform).
1) 4n /15
2) 8n/15
3) 16n /15
4) 32n / 15 

A chain is held on a friction-less table with one third of its length hanging over the edge. The total length of the chain is 1 and its mass is m. Find the work required to pull the hanging part back to the table.

1) 2mgl    2) mgl / 5    3) mgl / 9   4) mgl / 18  

An object, moving with a speed of 6.25 m/s, is decelerated at a rate given by  where v is the instantaneous speed. The time taken by the object, to come to rest, would be

1) 1 s 2) 2 s  3)  4 s  4)  8s