Two bodies of masses m and 4m are placed at a distance r. The gravitational potential at a point on the line joining them where the gravitational field is zero, is

Six particles are placed on the corners of a regular hexagon of side 4 m. Each starts from rest with a constant speed of 10 m/s such that direction of motion of each is always pointing towards the next in order. They finally converge. The distance covered by each particle before they converge is

1) 4 m    2) 8 m  3) 12 m   4) 16 m

A current of 50 A is passed through a straight wire of length 6 cm,then the magnetic induction at a point 5 cm from the either end of the wire is (1 gauss =10⁻⁴ T)

1) 2.5 gauss
2) 1.25 gauss
3) 1.2 gauss
4) 3.0 gauss

 The one mole of an ideal gas is compressed adiabatically from temp. 27⁰ C to 102⁰ C the work done in the process will be : (r = 1.5)

(1) 1000.25 J
(2) – 1245 J
(3) -928.75 J
(4) - 622.5 J

In a reversible ideal engine, 650 J of heat comes from source of 450 K, heat rejected to sink at 225 K is

1) 325 J
2) 625 J
3) 700 J
4) 800 J

An 8cm long wire carrying a current of 10A is placed inside a solenoid perpendicular to its axis. If the magnetic field inside the solenoid is 0.3T, then magnetic force on the wire is

1) 0.14N
2) 0.24N
3) 0.34N
4) 0.44N

A reference frame attached to the Earth
 
 1) is an inertial frame by definition.
 2) is an inertial frame because Newton's laws of motion are applicable inside it.
 3) is not an inertial frame because the Earth moves with respect to the Sun.
 4) cannot be an inertial frame of reference because of the Earth's rotation and revolution.

Water drops are falling from a water tap at a regular interval of one second; such that when first drop reaches the ground, the fourth drop just leaves the water tap. Find height of water tap. [g = 10 m/s²]

1) 10   2) 45  3) 25   4) 15

Air is pumped into an automobile tube upto a pressure of 200 kPa in the morning when the air temperature is 22$$^{\circ}$$C. During the day, temperature rises to 42$$^{\circ}$$C and the tube expands by 2 %. The pressure of the air in the tube at this temperature, will be approximately

1) 212 kPa
2) 209 kPa
3) 206 kPa
4) 200 kPa

A ray of light is incident on the hypotenuse of a right-angled prism after travelling parallel to the base inside the prism. If μ is the refractive index of the material of the prism, the maximum value of the base angle for which light is totally reflected from the hypotenuse is