List of practice Questions

Secondary structure of protein refers to:
A source producing sound of frequency 170 Hz is approaching a stationary observer with a velocity of 17 m/s. The apparent change in the wavelength of sound heard by the observer is (speed of sound in air = 340 m/s):
Consider the following reactions: \[ \text{NaCl} + \text{K}_2\text{Cr}_2\text{O}_7 + \text{H}_2\text{SO}_4 (\text{Conc.}) \rightarrow (A) + \text{Side products} \] \[ (B) + \text{H}_2\text{SO}_4 (\text{dilute}) + \text{H}_2\text{O}_2 \rightarrow (C) + \text{Side products} \] The sum of the total number of atoms in one molecule each of (A), (B) and (C) is __________.
Xenon hexafluoride on partial hydrolysis produces compounds 'X' and 'Y'. Compounds 'X', 'Y' and the oxidation state of Xe are respectively:
The edge length of unit cell of a metal having molecular weight 75 g/mol is 5 Å which crystallizes in cubic lattice. If the density is 2 g/cc, then find the radius of the metal atom. (\( N_A = 6 \times 10^{23} \)) Give the answer in pm.
Consider the following statements: I. Increase in concentration of reactant increases the rate of a zero order reaction. II. Rate constant \( k \) is equal to collision frequency if \( E_a = 0 \). III. Rate constant \( k \) is equal to collision frequency if \( E_a = \infty \). IV. \( \ln k \) vs \( T \) is a straight line. V. \( 1/T \) vs \( \ln k \) is a straight line. Correct statements are:
The following circuit represents
A particle of mass 10 kg is moving with a velocity of 5 m/s. The kinetic energy of the particle is:
The root mean square velocity of hydrogen molecules at 300 K is 1930 meters/second. The velocity of oxygen molecules at 1200 K will be:
A magnetic field of 5 T is applied perpendicular to a coil with 5 turns. The induced emf in the coil is 10 V. The rate of change of magnetic flux is:
A parallel plate capacitor with air between the plates has a capacitance of 3 μF. Calculate the capacitance if the distance between the plates is reduced by half and the space between them is filled with a substance of dielectric constant \( k \).
A body executing SHM has displacement \( y = A \cos \omega t \). Identify the graph which represents the variation of potential energy (PE) as a function of time \( t \) and displacement.
A radioactive sample contains 5 × 10\(^7\) kg of each of two isotopes A and B with half-lives of 5 days and 8 days respectively. The fraction of A that decays in 3 days after a period of 3 days is:
A string of length 3 m and mass 0.035 kg is stretched with a tension of 50 N. The speed of the wave on the string is:
Two bodies of the same mass are projected with the same velocity at an angle \( 30^\circ \) and \( 60^\circ \) respectively. The ratio of their horizontal ranges will be:
Two point charges \( +3 \, \mu C \) and \( +8 \, \mu C \) repel each other with a force of 40 N. If a charge of \( -5 \, \mu C \) is added to each of them, then the force between them will become:
A sphere rolls down an inclined plane of inclination \( \theta \). What is the acceleration as the sphere reaches the bottom?
A given ray of light suffers minimum deviation in an equilateral prism P. Additional prisms Q and R of identical shape and same material such that P, Q, and R are now combined as shown in figure. The ray will now suffer
The current in the 120 \( \Omega \) resistor shown in the circuit is
Identify the correct statement.
The distance travelled by a particle starting from rest and moving with an acceleration \(3 \, \text{m/s}^2\) in the third second is:
Photocathode work function is \( 1 \, \text{eV} \). Light of wavelength \( \lambda = 3000 \, \text{Å} \) falls on it. The photoelectron comes out with a maximum velocity of \( 1 \times 10^6 \, \text{m/s} \). What is the energy of the photon?
A steam engine operating between \( 100^\circ C \) and \( 40^\circ C \) has an efficiency of \( 25% \). The heat absorbed by the engine is:
Two point charges \( +q \) and \( -q \) are placed at a distance \( d \) apart. The electric potential at the midpoint will be
Two wires A and B are of the same material. Their lengths are in the ratio \( 1:2 \) and the diameter is in the ratio \( 2:1 \). If they are pulled by the same force, then increase in length will be in the ratio of