List of top Questions asked in JCECE- 2005

An automobile travelling at 50 km/h, can be stopped at a distance of 40 m by applying brakes. If the same automobile is travelling at 90 km/h, all other conditions remaining same and assuming no skidding, the minimum stopping distance in metres is:

If a transformer of an audio amplifier has output impedance 8000 0 and the speaker has input impedance of 80, the primary and secondary turns of this transformer connected

A rifle shoots a bullet with a muzzle velocity of $ 500\,m{{s}^{-1}} $ at a small target 50 m away. To hit the target the rifle must be aimed: (Take $ g=10\,m{{s}^{-2}} $ )

What is potential of platinum wire dipped into a solution of 0.1 M in $ S{{n}^{2+}} $ and 0.01 M in $ S{{n}^{4+}}? $

A stationary body of mass m explodes into the three parts having masses in the ratio 1:3:3. The two fractions with equal masses move at right angles to each other with a velocity of $ 1.5\,m{{s}^{-1}}. $ The velocity of the third part is:

A particle moves along Y-axis in such a way that its $ y- $ coordinate varies with time $ t $ according to the relation $ y=3+5t+7{{t}^{2}}. $ The initial velocity and acceleration of the particle are respectively:

The matrix $\left[\begin{array}{ccc}5& 10& 3\\ -2& -4& 6\\ -1& -2& b\end{array}\right]$is a singular matrix, if b equals

A heavy brass sphere is hung from a weightless inelastic spring and as a simple pendulum its time period of oscillation is T. When the sphere is immersed in a non-viscous liquid of density 1/10 that of brass, it will act as a simple pendulum of period :

The .examples of diamagnetic, paramagnetic and ferromagnetic materials are respectively:

An $ \alpha - $ particle of mass m suffers one dimensional elastic collision with a nucleus of unknown mass. After the collision the $ \alpha - $ particle is scattered directly backwards losing 75% of its kinetic energy. The mass of the unknown nucleus is:

The resistors are connected as shown in the figure below. Find the equivalent resistance between the points A and B.

Law of multiple proportions is illustrated by one of the following pairs:

The number of isomeric hexanes is:

A block of mass 2 kg rests on a plane inclined at an angle of $ {{30}^{o}} $ with the horizontal. The coefficient of friction between the block and surface is 0.7. The frictional force acting on the block is:

Which of the following overlaps leads to bonding?

$ Cis-trans $ isomers generally:

Which of the following statement is wrong?

Wurtz's reaction involves'the reduction of alkyl halide with:

The two optical isomers given below, namely, :

The coagulating power of an electrolyte for arsenious sulphide decreases in the order:

Radioactive decay series of uranium is denoted as:

In one of the following reactions $ \text{HN}{{\text{O}}_{\text{3}}} $ does not behave as an oxidizing agent. Identify it:

Conversion of benzaldehyde to 3-phenyl-prop-2-en-1-oic acid is:

A person is standing in an elevator. In which situation he finds his weight less?

The radius of sphere is measured to be $ (2.1\,\pm \,0.5)\,cm. $ Calculate its surface area with error limits: