Recent questions

The inert gas at room temperature is:

Which of the following is the characteristic smell of benzaldehyde?
A)-Fish like smell
B)-Bitter almond like
C)-Pungent smell
D)-Rotten egg like smell

The dominant mechanisms of motion of change carriers in forward and reverse biased silicon (P-N) junction are
A)-drift in forward bias, diffusion in reverse bias
B)-diffusion in forward bias, drift in reverses bias
C)-diffusion in both forward and reverse bias
D)-drift in both forward and reverse bias

In an intrinsic semiconductor at room temperature, number of electrons and holes are
A)-unequal
B)-equal
C)-infinite
D)-zero

Write the chemical formula for the following compound.

The solubilities of carbonates decrease down the magnesium group due to decrease in
A)-lattice energies of solids
B)-hydration energies of carbon
C)-inter ionic attraction
D)-entropy of solution formation

A particle of mass 'm' with charge 'q' moving with a uniform speed 'v' normal to a uniform magnetic field 'B', describe a circular path of radius 'r'. Derive expression for(i) time period of revolution(ii) kinetic energy of the particle

The co-ordination number of hexagonal close packing:
A)-4
B)-6
C)-8
D)-12

Which of the following is known as the Black lead?
A)- Charcoal
B)-Diamond
C)-Graphite
D)-Fullerenes

A balloon starts rising form the earth's surface. The ascension rate is constant and equal to v0. Due to the wind, the balloon gathers the horizontal velocity component vx = k y, where k is a constant and y is the height of ascent. Find how the following quantities depend on the height of ascent.

Out of the four alternatives given below, you have to select one set of letters that will maintain the relationship on the two sides of the sign ': :' the same if it is substituted for the question mark '?'

Explain some of the modifications of leaves found in plants.

Why do some plants have to trap insects?

Prove that if the function is differentiable at a point C then it is also continuous at that point.

A bulb is made using two filaments. A switch selects whether the filaments are used individually or in parallel. when used with a 15V battery, the bulb can be operated at 5 W, 10 W or 15 W . What should be the resistances of the filaments?

Which one of the following is the most important halogen in terms of preparation of halogen derivatives of alkane?
A)-Bromine
B)-Chlorine
C)-Iodine
D)-Fluorine

Common variety of polyester is_____ | Chemistry Questions
A)-terylene
B)-polymer
C)-viscose
D)-spinneret

Sulphide ores of metals are usually concentrated by froth floatation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching?
A)-Argentite
B)-Sphalerite
C)-Galena
D)-Copper pyrite

How does a catalyst increase the rate of a reaction?
A)-By forming an intermediate complex
B)-By increasing activation energy
C)- By lowering the activation energy
D)-By changing equilibrium constant

Oxidation number of (C) in (HCCOH) is________.
A)-(+2)
B)-(+4)
C)-(+3)
D)-(0)