A current of \(5\) A is passing through a metallic wire of cross-sectional area \(4\times10^{-6}\) m². If the density of charge carriers of the wire is \(5\times10^{26}\) m^-3, then the drift velocity of the electrons will be:
1. \(1\times 10^2\) m/s
2. \(1.56 \times10^{-2}\) m/s
3. \(1.56 \times10^{-3}\) m/s
4. \(1\times 10^{-2}\) m/s

The numerical ratio of displacement to the distance covered is always:

The principle of LASER action involves:

A train is moving towards the east and a car is along the north, both at the same speed. The observed direction of the car to the passenger and the train is:
1. east-north direction
2. west-north direction
3. south-east direction
4. none of the above

Which of the following is a unipolar transistor?
1. p-n-p transistor
2. n-p-n transistor
3. field effect transistor
4. point contact transistor

A solid sphere and a hollow sphere of the same material and of the same size can be distinguished without weighing:

Point masses \(1,\) \(2,\) \(3\) and \(4\) kg are lying at the points \((0,0,0),\) \((2,0,0),\) \((0,3,0)\) and \((-2,-2,0)\) respectively. The moment of inertia of this system about the X-axis will be:
1. \(43~\mathrm{kg-m^2}\) 
2. \(34~\mathrm{kg-m^2}\) 
3. \(27~\mathrm{kg-m^2}\) 
4. \(72~\mathrm{kg-m^2}\) 

The radius of gyration of a body about an axis at a distance \(6~\mathrm{cm}\) from its centre of mass is \(10~\mathrm{cm}\). Then, its radius of gyration about a parallel axis through its centre of mass will be:
1. \(80~\mathrm{cm}\) 
2. \(8~\mathrm{cm}\) 
3. \(0.8~\mathrm{cm}\) 
4. \(80~\mathrm{m}\) 

A galvanometer can be changed into an ammeter by using:

A bullet of mass \(20\) g and moving with \(600\) m/s collides with a block of mass \(4\) kg hanging with the string. What is the velocity of a bullet when it comes out of the block, if the block rises to height \(0.2\) m after collision?
1. \(200\) m/s
2. \(150\) m/s
3. \(400\) m/s
4. \(300\) m/s