Physics Test-2...

A long insulated copper wire is closely wound as a spiral of 'N' turns. The spiral has an inner radius 'a' and an outer radius 'b'. The spiral lies in the X-Y plane and a steady current 'I' flows through the wire. The Z-component of the magnetic field at the center of the spiral is:

A motorcycle moving with a velocity of \(72 \mathrm{km} /\mathrm{h}r\) on a flat road takes a turn on the road at a point where the radius of curvature of the road is \(20\) \(\mathrm{m}\). The acceleration due to gravity is \(10 \mathrm{m} / \mathrm{s}^{2}\). In order to avoid skidding, he must not bend with respect to the vertical plane by an angle greater than:

Which of the following is correct regarding eddy currents in the coil?

In the circuit shown the value of \(I\) in ampere is:

To take the longest possible jump, an athlete should make an angle of _________________.

A car of mass \(1\) tonne is moving with a speed of \(30 \mathrm{~m} / \mathrm{s}\). It suddenly applies the brakes and stops after moving a certain distance \(d\). The frictional force between the tyres and road is \(F=k \sqrt{x}\) where \(x\) is the distance covered. If \(k=1000\), the distance d covered by the car before stopping is-

A tube of length \(\mathrm{L}\) is filled completely with an incompressible liquid of mass \(\mathrm{M}\) and closed at both the ends. The tube is then rotated in horizontal plane about one of its ends with a uniform angular velocity \(\omega\). The force exerted by the liquid at the other end is:

Which type of waves are used to communicate with the artificial satellite:

In the relation \(p=\frac{\alpha}{\beta} \mathrm{e}^{-\frac{\alpha z}{k \theta}}, p\) is the pressure, \(z\) the distance, \(k\) is Boltzmann constant and \(\theta\) is the temperature, the dimensional formula of \(\beta\) will be:

Ultraviolet radiations of 5.4 eV fall on an aluminium surface (work function 3.4 eV). The kinetic energy (in joule) of the fastest electron emitted is approximate.

Consider the earth as a uniform sphere of mass M and radius R. Imagine a straight smooth tunnel made through the earth which connects any two-point on its surface. Show that the motion of a particle of mass m along this tunnel under the action of gravitation would be simple harmonic. Hence, determine the time that a particle would take to go from one end to the other through the tunnel.

The gravitational field in a region is given by \(\overrightarrow{\mathrm{E}}=(3 \hat{\mathrm{i}}-4 \hat{\mathrm{j}}) \mathrm{N} \mathrm{kg}^{-1}\). Find out the work done(in joule) in displacing a particle by \(1 \mathrm{~m}\) along the line \(4 \mathrm{y}=3 \mathrm{x}+9\).

A flywheel of mass 6000 kg starts from rest and gets up to a speed of 20 rad/s in 2 minutes. The radius of gyration of the wheel is 100 cm. The average torque exerted on the flywheel is:

A point charge \(+10 \mu {C}\) is at a distance of \(5 {~cm}\) directly above the centre of a square of side \(10 {~cm}\), as shown in Fig. What is the magnitude of the electric flux through the square? (Hint: Think of the square as one face of a cube with edge \(10 {~cm}\) ).

If 600 ml of water at 60°C is mixed with 250 ml of water at 26°C, then what would be the final temperature (in°C) of the mixture: