List of top Physics Questions

A TV transmitting antenna is 70 m tall. If the receiving antenna is at ground level, then the area it can cover is: (Radius of Earth = 6400 km)

Find Y & Z in the following logic circuit:

A rectangular loop of area \(A\) lies in a uniform magnetic field \(B\) with its plane perpendicular to the field. If the loop rotates through \(90^\circ\) in time \(T/4\), then the induced emf during this interval is:

The electromagnetic waves: Visible, ultraviolet, infrared, gamma rays, X-rays in increasing order of their wavelengths is:

A radio antenna receiver works at \((10.5 \pm 4.5)\,MHz\) with an effective bandwidth of \(9\,MHz\). The corresponding wavelength bandwidth is:

A long straight wire carries a current of 10 A. An electron travels with velocity \(5 \times 10^6\,m\,s^{-1}\) at a distance 0.1 m from it, in a direction opposite to the current. Estimate the force experienced by the electron.

On the magnetic meridian at some place of the Earth’s surface the vertical component of Earth’s magnetic field is \(0.433\,G\) and the dip angle is \(60^\circ\). Then the magnetic field of the Earth at this place is:

In an oscillating LC circuit, \(L = 1.6\,mH\), \(C = 4\,\mu F\). If the maximum charge is \(4 \times 10^{-6}\,C\), then the maximum current is:

A spherical shell of radius \(R\) has charge \(Q\) uniformly distributed over its surface. The work done in this process is:

Two concentric circular arcs of radii 2 m and 3 m have linear charge densities \( \alpha \lambda \) and \( \lambda \) respectively as shown in the figure. The condition for the electric potential to vanish at the common center is (electric potential = 0 at infinity):

A small sphere of charge \(50\,\mu C\) and mass \(5\,g\) is attached to a horizontal light string and placed in a uniform electric field which makes an angle \(30^\circ\) with the horizontal. The opposite end of the string is attached to a vertical wall. If the sphere is in static equilibrium and the string is horizontal, then the tension in the string is: (Take \(g = 10\,m\,s^{-2}\))

Two parallel conductors a and b separated by distance \(d\) carry the same current. If the distance is doubled, the ratio of forces on conductor b before and after separation is:

The equivalent resistance of the circuit shown in the figure between points A and B is:

10 W is to be delivered to a device via a wire having resistance \(2\,\Omega\). If 20 V is the voltage across the device, the power wasted in the process is:

An object O is placed in front of two thin coaxial convex lenses A and B of focal lengths 24 cm and 9 cm respectively. The object is 6 cm to the left of lens A. If the final image is formed 18 cm to the right of lens B, find the separation between the lenses. (Lens A is placed left of lens B)

In which of the following processes does the internal energy of the gas remain unaffected?

The resolving power of a microscope can be increased by selecting an appropriate medium between the object and objective lens. For a fixed wavelength of light, resolving power increases with:

A pipe of length 80 cm is open at both ends. A second pipe, closed at one end, has the same fundamental frequency as the open pipe. The length of the second pipe is:

The density of a gas is 1 molecule cm\(^{-3}\). If the molecular diameter is \(1 \times 10^{-8}\) cm, then the mean free path of the molecules is:

A heat engine operates between a cold reservoir at temperature 300 K and a hot reservoir at temperature \(T_1\). It takes 200 J of heat from the hot reservoir and delivers 120 J of heat to the cold reservoir in a cycle. The minimum temperature \(T_1\) of the hot reservoir is:

If the potential energy at a displacement \(x\) is numerically equal to the square root of potential energy at a displacement \(y\), then (where \(\omega\) is angular velocity):

An object is thrown directly away from Earth's surface. Its initial speed is \(V_0\) and escape velocity is \(V_E\). If the object reaches a distance of \(\frac{4R}{3}\) from the centre of the Earth, then the ratio \(\frac{V_E}{V_0}\) is:

A body of mass 0.7 kg executes simple harmonic motion of amplitude 7 cm and period 0.2 s. The magnitude of the maximum force on it is:

A horizontal metal rod of diameter 4 cm projects 6 cm from a wall. The shear modulus of the metal is \(3 \times 10^{10}\, N\,m^{-2}\). An object of mass 1100 kg is suspended from the free end of the rod. The free end of the rod moves down by a distance. (Take \(g = 10\,m\,s^{-2}\), neglect mass of rod)

According to the law of equipartition of energy, the molar specific heat of solids at low temperatures is equal to (R = universal gas constant):