JEE Main 2018 Question Paper

Phenol reacts with methyl chloroformate in the presence of NaOH to form product A. A reacts with Br2 to form product B. A and B are respectively :

The combustion of benzene (l) gives CO2(g) and H2O(l). Given that heat of combustion of benzene at constant volume is -3263.9 kJ mol-1 at 25oC ; heat of combustion (in kJ mol-1) of benzene at constant pressure will be - (R = 8.314 JK-1 mol-1)

How long (approximate) should water be electrolysed by passing through 100 amperes current so that the oxygen released can completely burn 27.66 g of diborane ? (Atomic weight of B = 10.8 u)

Total number of lone pair of electrons in I3- ion is

At 518oC, the rate of decomposition of a sample of gaseous acetaldehyde, initially at a pressure of 363 Torr, was 1.00 Torr s-1 when 5% had reacted and 0.5 Torr s-1 when 33% had reacted. The order of the reaction is :

If the curves y2 = 6x, 9x2 + by2 = 16 intersect each other at right angles, then the value of b is :

Tangent and normal are drawn at P(16, 16) on the parabola y2 = 16x, which intersect the axis of the parabola at A and B, respectively. If C is the centre of the circle through the points P, A and B and ∠CPB = θ, then a value of tanθ is

Let the orthocentre and centroid of a triangle be A(-3, 5) and B(3, 3) respectively. If C is the circumcentre of this triangle, then the radius of the circle having line segment AC as diameter, is:

If the tangent at (1, 7) to the curve x2 = y - 6 touches the circle x2 + y2 + 16x + 12y + c = 0 then the value of c is :

The sum of the co-efficients of all odd degree terms in the expansion of x+x3-15+x-x3-15, (x > 1) is-

For an RLC circuit driven with voltage of amplitude vm and frequency w0 = 1LC the current exhibits resonance. The quality factor, Q is given by :

In an a. c. circuit, the instantaneous e.m.f. and current are given by e = 100 sin 30 t i = 20 sin 30t-π4 In one cycle of a.c., the average power consumed by the circuit and the wattless current are, respectively.

An electron from various excited states of hydrogen atom emit radiation to come to the ground state. Let λn, λg be the de Broglie wavelength of the electron in the nth state and the ground tate respectively. Let Λn be the wavelength of the emitted photon in the transition from the nth state to the ground state. For large n, (A, B are constants)

If the series limit frequency of the Lyman series is vL, then the series limit frequency of the Pfund series is :

A parallel plate capacitor of capacitance 90 pF is connected to a battery of emf 20V. If a dielectric material of dielectric constant K = 53 is inserted between the plates, the magnitude of the induced charge will be :-