The frequency of a photon whose energy is 66.3 eV would be
(Given \( h = 6.63 \times 10^{-34} \text{ Js} \))

An electromagnet has stored 540 J of magnetic energy when a current of 6 A exists in its coil. What is the value of average emf induced, if the current is reduced to zero in 0.54s?

A radioactive isotope has half-life of ' \(K\) ' years. How long will it take, so that activity reduces to \(6 . 2 5 \%\) of its original value?

Arrange the following electromagnetic waves in the increasing order of their wavelength.
(A) X-rays
(B) Radio waves
(C) Gamma rays
(D) Microwaves
Choose the correct answer from the options given below:

The external diameter of a 5 m long hollow copper tube is 10 cm and the wall thickness is 5 mm. If the specific resistance of copper is \( 1.7 \times 10^{-8} \text{ }\Omega\text{m} \), the resistance of the tube will be:

Choose the correct phase relationship between the current and the applied voltage in an a.c. circuit.
(A) In a pure resistive circuit, the current is in phase with the applied voltage.
(B) In a pure inductive circuit, the current lags behind the voltage by a phase angle of 90°.
(C) In a pure inductive circuit, the current leads the voltage by a phase angle of 90°.
(D) In a pure resistive circuit, the current is not in phase with the applied voltage.
Choose the correct answer from the options given below:

When temperature of a ferromagnetic material is increased by 20%, what is the percentage change in it's magnetic susceptibility?

Arrange the wavelengths of the following radiations in the decreasing order: \( \lambda_{visible}, \lambda_{X-rays}, \lambda_{radiowaves}, \lambda_{\gamma-rays} \)

Interstitial transition metal compounds
(A) have higher melting points than those of pure metals.
(B) have more reactivity than those of pure metals.
(C) are non-stoichiometric compounds.
(D) formed when small atoms like H, C or N are trapped inside the crystal lattice of the metals.
Choose the correct answer from the options given below:

The arrangement of the nuclei in a normal embryo sac from the chalazal to micropylar end in dicots is -

A 95% confidence interval states that the population mean is greater than 152 and less than 160.
If \(\sigma=15\) and \(Z_{0.025}=1.96\), then what sample size was used in the study?

Read the passage carefully and answer the Questions
Molar conductivity \(\left(\Lambda_m\right)\) of a solution at a given concentration (c) is the conductance of volume, V of solution, containing one mole of electrolyte kept between the two electrodes with area of cross-section A and at a distance of unit length. It increases with the decrease in concentration and when the concentration approaches zero, the molar conductivity is called limiting molar conductivity \(\left(\Lambda_m^0\right)\). For a strong electrolyte, \(\Lambda_m\) increases linearly with dilution and is given by \(\Lambda_m=\Lambda_m^0-A c^{1 / 2}\). The value of the constant A for a given solvent depends on the type of electrolyte along with temperature. According to Kohlrausch law, the value of \(\left(\Lambda_m^0\right)\) for an electrolyte is A\(\Lambda_m^0=\nu_{+} \lambda_{+}^0+\nu_{-} \lambda_{-}^0\), where \(\nu_{+}\)and \(\nu_{-}\) are the number of cations and anions, respectively, per molecule of the electrolyte and \(\lambda_{+}^0\) and \(\lambda_{-}^0\) are limiting molar conductivities of cation and anion, respectively. Kohlrausch law
finds many applications, like determining the solubility of a sparingly soluble salt, determining the degree of dissociation\(\left(\Lambda_m / \Lambda_m^0\right)\), and the dissociation constant of a weak electrolyte.
If the equivalent conductivity of 1 M Phthalic acid is \(12.8 S cm ^2 eq ^{-1}\) and the limiting equivalent conductivities of the
hydrogen and Phthalate ions are 42 and \(288.42 S cm ^2 eq ^{-1}\), respectively, the degree of dissociation of Phthalic acid will be :

A current of \(10^{-7} A\) produces 50 division deflection in a galvanometer. The figure of merit would be :