Iit – jee screening examination sample paper PART 1

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Q1. A particle of charge q and mass m moves in a circular orbit of radius r
with angular speed w. The ration of the magnitude of its magnetic to that of
its angular momentum depends on
(a) and q (b) q and m
(c) q and m (d) and m
Q2. Two vibrating strings of the same material but lengths L and 2L have
radii 2r and r respectively. They are stretched under the same tension. Both
the strings vibrate in their fundamental modes, the one of length L with
frequency v1 and the other with frequency v2. The ratio v1 / v2 is given by:
(a) 2 (b) 4
(c) 8 (d) 1
Q3. Image an atom made up of a proton and a hypothetical particle of double
the mass of the electron but having the same charge as the electron. Apply
the Bohr atom model and consider all possible transactions of this
hypothetical particle to the first excited level. The longest wavelength
photon that will be emitted has wavelength (given in terms of the Rydberg
constant R for the hydrogen atom) equal to
(a) 9/(5R) (b) 36/(5R)
(c) 18/(5R) (d) 4/R
Q4. Among H2 O, H2 S, H2 Se and H2 Te, the one with the highest boiling
point is
(a) H2 O because of hydrogen bonding.
(b) H2 Te because of higher molecular weight.
(c) H2 S because of hydrogen bonding.
(d) H2 Se because of lower molecular weight.
The questions below (5 to 9) consist of an ‘Assertion’ in column 1 and the
‘Reason’ in column 2. Use the following key to choose the appropriate
answer.
(a) If both assertion and reason are CORRECT and reason is the
CORRECT explanation of the assertion.
(b) If both assertion and reason are CORRECT, but reason is NOT the
CORRECT explanation of the assertion.
(c) If assertion is CORRECT, but reason in INCORRECT.
(d) If assertion is INCORRECT but reason is CORRECT.
Assertion (column 1) Reason (column 2)0
Q5. The first ionization energy of be 2p orbital is lower in energy
Greater than that of B. than 2s.
Q6. 1-butene on reaction with HBr in It involves the formation of a
The presence of a peroxide produces primary radical.
Bromobutane
Q7. The heat absorbed during the The volume occupied by the
Isothermal expansion of an ideal molecules of an ideal gas
Gas vacuum is zero against is zero
Q8. The pressure of a fixed amount an Frequency of collisions and
ideal gas is proportional to its their impact both increase in
temperature. Proportion to the square root
of temperature.
Q9. Phenol is more reactive than benzene In the case of phenol, the
Towards electrophilic substitution intermediate carbocation is
Reaction. More resonance stabilized.
Q10. Let f () = sin (sin + sin 3 ). Then f ()
(a) ≥0 only when ≥0 (b) ≤0 for all real 
(c) ≥for all real (d) ≤0 only when ≤0
Q11. If x+y=k is normal to y² =12x, then k is
(a) 3 (b) 9
(c) -9 (d) -3
Q12. The dimension of (1/2) oE² (o: permittivity of free space; E: electric
field) is
(a) ML T1 (b) ML2 T 2
(c) MLT2 (d) ML2 T1
Q13. The electron in a hydrogen atom makes a transition from an excited
state to the ground state. Which of the following statements is true?
(a) Its kinetic energy increases and its potential and total energies
decrease.
(b) Its kinetic energy decreases, potential energy increases and its total
energy remains the same.
(c) Its kinetic and total energies decrease and its potential energy
increases.
(d) Its kinetic, potential and total energies decrease.
Q14. In a double slit experiment, instead of taking slits of equal widths, one
slit is made twice as wide as the other. Then, in the interference pattern
(a) the intensities of both the maxima and the minima increase.
(b) the intensity of the maxima increases and the minima has zero
intensity.
(c) the intensity of the maxima decreases and the minima has zero
intensity.
Q15. A hollow double concave lens is made up of very thin transparent
material. It can be filled with air or either of two liquids L1 and L2 having
refractive indices n1 and n2 respectively (n2 n1 1). The lens will diverge a
parallel beam of light if it is filled with
(a) air and placed in air.
(b) Air and immersed in L1
(c) L1 and immersed in L2
(d) L2 and immersed in L1
Q16. A coil of wire having finite inductance and resistance has a conducting
ring placed coaxially within it. The coil is connected to a battery at time t=0,
so that a time dependent current I1 (t) starts flowing through the coil. If I2 (t)
is the current induced in the ring, and B(t) is the magnetic field at the axis of
the coil due to I1 (t), then as a function of time (t > 0), the product I2 (t) B(t)
(a) increases with time
(b) decreases with time
(c) does not vary time
(d) passes through a maximum.

Q17. Starting with the same initial conditions, an ideal gas expands from
volume V1 to V2 in three different ways. The done by the gas is W1 if the
process is purely isothermal, W2 if purely isobaric and W3 if purely
adiabatic. Then
(a) W2 >W1 >W3
(b) W2 >W3 >W1
(c) W1 >W2 >W3
(d) W1 >W3 >W2
Q18. Two radioactive materials X1 and X2 have decay constants 10and 
respectively. If initially they have the same number of nuclei, then the ratio
of the number of nuclei of X1 to that of X2 will be 1/e after a time
(a) 1/(10)
(b) 1/(11)
(c) 11/(10)
(d) 1/(9)
Q19.In a compound microscope, the intermediate image is
(a) virtual, erect and magnified
(b) real, erect and magnified
(c) real, inverted and magnified.
(d) Virtual, erect and reduced.
Q20. Electrons with energy 80 ke V are incident on the tungsten target of an
X-ray tube. K shell electrons of tungsten have -72.5 ke V energy. X-ray
emitted by the tube contain only.
(a) a continuous X-ray spectrum (Bremsstrahlung) with a minimum
wavelength of ∼0.155 Å.
(b) a continuous X-ray spectrum (bremsstrahlung) with all wavelengths.
(c) the characteristic X-ray spectrum of tungsten.
(d) a continuous X-ray spectrum (Bremsstrahlung) with a minimum
wavelength of ∼0.155 Å.
Q21. An ionized gas contains both positive and negative ions. If it is
subjected simultaneously to an electric field along the+x direction and a
magnetic field along the +z direction, then
(a) positive ions deflect towards+y direction and negative ions towards-y
direction.
(b) all ions deflect towards +y direction.
(c) all ions deflect towards-y direction.
(d) positive ions deflect towards –y direction and negative ions towards
+y direction.

Q22. Three charges Q, + q and + q are placed at the vertices of a rightangled
isosceles triangle as shown. The net electrostatic energy of the
configuration is zero Q is equal to
(a) angular velocity and total energy (kinetic and potential)
(b) total angular momentum and total energy.
(c) Angular velocity and moment of inertia about the axis of rotation.
(d) Total angular momentum and moment of inertia about the axis of
rotation.
Q23. A large open tank has two holes in the wall. One is a square hole of
side L at a depth y from the top and other is a circular hole of radius R at a
depth 4y from the top. When the tank is completely filled with water, the
quantities of water flowing out per second from both holes are the same.
Then, R is equal to
(a) L
√2
(b) 2L
(c) L
(d) L
2
Q24. Which of the following compounds will exhibit geometrical
isomerism?
(a) 1-pheny1-2 butene
(b) 3-pheny-1-butene
(c) 2-pheny-1-butene
(d) 1,1-dipheny0-1-propene
Q25.Benzoyl chloride is prepared from benzoic acid by
(a) Cl2 , hv
(b) SO2 CL2
(c) SOCl2
(d) Cl2 , H2 O
Q26.The correct order of radii is
(a) NBeB
(b) F- O² N3-
(c)NaLiK
(d) Fe3+ Fe2+ F4+

Q27. The number of nodal planes in a px orbital is
(a) one
(b) two
(c) three
(d) zero
Q28. Which of the following has the highest nucleophilicity?
(a) F-
(b)OH-
(c) CH-
3
(d) NH-
2
Q29. The rms velocity hydrogen is √7 times the rms velcoty of nitrogen. If T
is the temperature of the gas.
(a) T(H2 ) = T(N2 )
(b) T(H2 )T(N2 )
(c) T(N2 ) T(N2 )
(d) T(N2 ) = √7 T(N2 )
Q30. The electronic configuration of an element is 1s2 2s2 2p6 3s2 3p6 3d5 4s1
(a) Excited state
(b) Ground state
(c) Cationic form
(d) anionic state
Q31. The chemical processes in the production of steel from haematite ore
involves
(a) reduction
(b)oxidation
(c) reduction followed by oxidation
(d) oxidation followed by reduction.
Q32. Among the following] identify the species with an atom in +6
oxidation state
(a) MnO-
4
(b) Cr(CN)3-
6
(c) NiF2-
6
(d) CrO2 CI2

Q32. The compressibility of a gas is less than unity at STP. Therefore,
(a) Vm 22.4 litres
(b) Vm 22.4 litres
(c) Vm = 22.4 litres
(d) Vm 44.8 litres
Q33. Among the following, the strongest base is
(a) C6H5NH2
(b) P-NO2-C6H4NH2
(c) m-NO2-C6H4NH2
(d) C6H5CH2NH2
Q34. When two reactants, A and B are mixed to give products C & D, the
reaction quotient, Q, at the initial stages of the reaction
(a) is zero
(b) decreases with time
(c) is independent of time
(d) increases with time