For the reaction:
at 300K
Hence is :-
2.7k cal
-2.7 k cal
9.3k cal
-9.3k cal
A thermodynamic system undergoes cyclic process ABCDA as shown in fig. the work done by the system in the cycle is:
A monoatomic gas at a pressure P, having a volume V expands isothermally to a volume 2 V, and then adiabatically to a volume 16 V. the final pressure of the gas is:
64 P
32 P
16 P
A body of mass (4m) is lying in x-y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass (m) move perpendicular to each other with equal speeds (V). The total Kinetic energy generated due to explosion is
seems logical .we assume that the 3rd part ie mass 2m goes in (-x-y) plane though the problem does not specify.How to explain that mass 2m does not move in Z direction?
Steam at 100^{o} C is passed into 20 g of water at 10^{o} C. When water acquires a temperature of 80^{o} C, the mass of water present will be:
[Take specific heat of water = 1 cal g^{-1} ^{o}C^{ -1} and latent heat of steam = 540 cal g^{-1}]
24 g
31.5 g
42.5 g
22.5 g
Copper of fixed volume 'V' is drawn into wire of length 'l'. When this wire is subjected to a constant force'F', the extension produced in the wire is . Which of the following graphs is a straight line?
A certain number of spherical drops of a liquid of radius 'r' coalesce to form a single drop of radius 'R' and volume 'V'. If 'T' is the surface tension of the liquid, then:
Energy is neither released nor absorbed.
If the focal length of objective lens is increased then magnefying power of:
microscope will increase but that of telescope decrease.
microscope and telescope both will increase.
microscope and telescope both will decrease.
microscope will decrease but that of telescope increase.
In the Young's double-slit experiment, the intensity of light at a point on the screen where the path difference is is K, ( being the wave length of light used). The intensity at a point where the path difference is , will be:
A beam of light from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between first dark fringes on either side of the central bright fringe is:
1.2 cm
1.2 mm
2.4 cm
2.4 mm
The ratio of the accelerations for a solid sphere (mass 'm' and radius 'R') rolling down and incline of angle '' without slipping and slipping down the incline without rolling is
5:7
2:3
2:5
7:5
The oscillation of a body on a smooth horizontal surface is represented by the equation,
X = A cos ( t)
where, X = displacement at time t
= frequency of oscillation
Which one of the following graphs shows correctly the variation of 'a' with 't'?
The number of possible natural oscillation of air column in a pipe closed at one end of length 85 cm whose frequencies lie below 1250 Hz are:
( velocity of sound = 340 ms^{-1})
4
5
7
6
In the following reaction, the product (A)
A speeding motorcyclist sees traffic jam ahead of him. He slows down to 36 km/hour. He finds that traffic has eased and a car moving a head of him at 18 km/hour is honking at a frequency of 1392 Hz. If the speed of sound is 343 m/s, the frequency of the honk as heard by him will be:
1332 Hz
1372 Hz
1412 Hz
1464 Hz
(i)
(ii)
Role of hydrogen peroxide in the above reactions is respectively -
Oxidizing in (i) and reducing in (ii)
Reducing in (i) and oxidizing in (ii)
Reducing in (i) and (ii)
Oxidizing in (i) and (ii)
Which of the following organic compounds has same hybridization as its combustion product ?
Ethane
Ethyne
Ethene
Ethanol
The weight of silver (at wt.=108) displaced by a quantity of electricity which displaces 5600 mL of O_{2} at STP will be:
5.4 g
10.8 g
54.9 g
108.0 g
Be^{2+} is isoelectronic with which of the following ions?
H^{+}
Li^{+}
Na^{+}
Mg^{2+}
Magnetic moment 2.83 BM is given by which of the following ions?
(At nos. Ti=22, Cr=24, Mn=25, Ni=28):-