List of practice Questions

An electric bulb is rated as 200 W. What will be the peak magnetic field at 4 m distance produced by the radiations coming from this bulb? Consider this bulb as a point source with 3.5% efficiency.
The light of two different frequencies whose photons have energies 3.8 eV and 1.4 eV respectively, illuminate a metallic surface whose work function is 0.6 eV successively. The ratio of maximum speeds of emitted electrons for the two frequencies respectively will be
Two light beams of intensities in the ratio of 9 : 4 are allowed to interfere. The ratio of the intensity of maxima and minima will be:
In Bohr’s atomic model of hydrogen, let K, P and E are the kinetic energy, potential energy and total energy of the electron respectively. Choose the correct option when the electron undergoes transitions to a higher level:
The equations of two waves are given by : 
y1 = 5 sin 2π(x – vt) cm
y2 = 3 sin 2π(x – vt + 1.5) cm
These waves are simultaneously passing through a string. The amplitude of the resulting wave is :

A resistance of 40 Ω is connected to a source of alternating current rated 220 V, 50 Hz. Find the time taken by the current to change from its maximum value to the rms value :

A plane of electromagnetic waves travels in a medium with a relative permeability of 1.61 and relative permittivity of 6.44. If the magnitude of magnetic intensity is 4.5 × 10–2 Am–1 at a point, what will be the approximate magnitude of electric field intensity?(Given: Permeability of free space μ0 = 4π × 10–7 NA–2, speed of light in vacuum c = 3 × 108 ms–1)

Choose the correct option from the following options given below :

\(120 \;g\) of an organic compound that contains only carbon and hydrogen gives \(330\) \(g\) of \(CO_2\) and \(270\) \(g\) of water on complete combustion. The percentage of carbon and hydrogen, respectively are
The energy of one mole of photons of radiation of wavelength \(300\) \(nm\) is (Given \(h\) = \(6.63 × 10^{–34}\)Js, \(N_A\) = \(6.02 × 10^{23}\) \(mol^{–1}\), \(c = 3 × 10^8\) \(ms^{–1}\))
The correct order of bond orders of \(C_2^{2-}, N_2^{2-}, O_2^{2-}\) is, respectively
For a first order reaction, the time required for completion of 90% reaction is ‘x’ times the half life of the reaction. The value of ‘x’ is (Given: In 10 = 2.303 and log 2 = 0.3010)
Metals generally melt at very high temperature. Amongst the following, the metal with the highest melting point will be
In the industrial production of which of the following, molecular hydrogen is obtained as a byproduct?
Two buses P and Q start from a point at the same time and move in a straight line and their positions are represented by XP(t) = αt + βt2 and XQ(t) = ft – t2. At what time, both the buses have same velocity?
A disc with a flat small bottom beaker placed on it at a distance R from its center is revolving about an axis passing through the center and perpendicular to its plane with an angular velocity ω. The coefficient of static friction between the bottom of the beaker and the surface of the disc is μ. The beaker will revolve with the disc if :

A solid metallic cube having total surface area 24 m2 is uniformly heated. If its temperature is increased by 10°C, calculate the increase in volume of the cube. 

(Given α = 5.0 × 10–4 °C–1).

The ratio of specific heats 

\((\frac{c_p}{c_v}) \)

in terms of degree of freedom (f) is given by:

For a particle in uniform circular motion, the acceleration a at any point P(R, θ) on the circular path of radius R is (when θ is measured from the positive x-axis and v is uniform speed):
Two metallic plates form a parallel plate capacitor. The distance between the plates is ‘d’. A metal sheet of thickness d/2 and of area equal to area of each plate is introduced between the plates. What will be the ratio of the new capacitance to the original capacitance of the capacitor?

Given below are two statements:

Statement-I : Susceptibilities of paramagnetic and ferromagnetic substances increase with decrease in temperature.

Statement-II : Diamagnetism is a result of orbital motions of electrons developing magnetic moments opposite to the applied magnetic field.

Choose the correct answer from the options given below:-

A long solenoid carrying a current produces a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of magnetic field will be equal to
A sinusoidal voltage V(t) = 210 sin 3000 t volt is applied to a series LCR circuit in which L = 10 mH, C = 25 μF and R = 100 Ω. The phase difference (Φ) between the applied voltage and resultant current will be:
The electromagnetic waves travel in a medium at a speed of 2.0 × 108 m/s. The relative permeability of the medium is 1.0. The relative permittivity of the medium will be
\(PCl_5\) is well known, but \(NCl_5\) is not. Because,