What is compound A in given below image?

Acetylene does not react with

(a) Na

(b) ammoniacal AgNO_{3}

(c) HC1

(d) NaOH

Which of the following ions has the maximum magnetic moment?

Why is used in space and submarines?

What is the number of bonds in ?

For an ideal gas, number of mol per liter in terms of its pressure *P, *temperature *T *and gas constant *R *is

Which of the following is a redox reaction?

What is difference between Prokaryotic cell and Eukaryotic cell.

Explain Cell Wall and Their Structure and Function

A bomb of mass 16 kg at rest explodes into two pieces of masses of 4 kg and 12 kg. The velocity of the 12 kg mass is 4 ms–1. The kinetic energy of the other mass is

A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?

A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle, the motion of the particle takes place in a plane. It follows that

A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement x is proportional to

A spring of spring constant 5 × 103 N/m is stretched initially by 5 cm from the unstretched position. Then the work required to stretch it further by another 5 cm is

A body is moved along a straight line by a machine delivering a constant power. The distance moved by the body in time t is proportional to

A spring of force constant 800 N/m has an extension of 5 cm. The work done in extending it from 5 cm 8. to 15cm is

If massenergy equivalence is taken into account, when water is cooled to form ice, the mass of water should

A ball whose kinetic energy is E, is projected at 6. an angle of 45° to the horizontal. The kinetic energy of the ball at the highest point of its flight will be

If N_{o} is the original mass of the substance of half-life period t_{1/2} = 5 years, then the amount of substance left after 15 years is:

A ball of mass 0.2 kg is thrown vertically upwards by applying a force by hand. If the hand moves 0.2 m which applying the force and the ball goes upto 2 m height further, find the magnitude of the force. Consider g = 10 m/s2

A block rests on a rough inclined plane making an angle of 30° with the horizontal. The coefficient of static friction between the block and the plane is 0.8. If the frictional force on the block is 10 N, the mass of the block (in kg) is

A marble block of mass 2 kg lying on ice when given a velocity of 6 m/s is stopped by friction in 10 s. Then the coefficient of friction is

A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and the spring reads 49 N, when the lift is stationary. If the lift moves downward with an acceleration of 5 m/s2, the reading of the spring balance will be

Three identical blocks of masses m = 2 kg are drawn by a force F = 10.2 N with an acceleration of 0.6 ms–2 on a frictionless surface,then what is the tension (in N) in the string between the blocks B and C

A light string passing over a smooth light pulley connects two blocks of masses m1 and m2 (vertically). If the acceleration of the system is g/8, then the ratio of the masses is

One end of a massless rope, which passes over P a massless and frictionless pulley P is C tied to a hook C while the other end is free.

Maximum tension that the rope can bear is 960 N. With what value of maximum safe acceleration (in ms–2) can a man of 60 kg climb on the rope?

When forces F1, F2, F3 are acting on a particle of mass m such that F2 and F3 are mutually perpendicular, then the particle remains stationary. If the force F1 is now removed then the acceleration of the particle is

When forces F1, F2, F3 are acting on a particle of mass m such that F2 and F3 are mutually perpendicular, then the particle remains stationary. If the force F1 is now removed then the acceleration of the particle is

A lift is moving down with acceleration a. A man in the lift drops a ball inside the lift. The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground are respectively

The kinetic energy needed to project a body of mass m from the earth surface (radius R) to infinity is

Energy required to move a body of mass m from an orbit of radius 2R to 3R is

If suddenly the gravitational force of attraction between Earth and a satellite revolving around it becomes zero, then the satellite will

If g is the acceleration due to gravity on the earth’s surface, the gain in the potential energy of an object of mass m raised from the surface of the earth to a height equal to the radius R of the earth is

The time period of an earth satellite in circular orbit is independent of

A satellite of mass m revolves around the earth of radius R at a height x from its surface. If g is the acceleration due to gravity on the surface of the earth, the orbital speed of the satellite is

The escape velocity for a body projected vertically upwards from the surface of earth is 11 km/s. If the body is projected at an angle of 45° with the vertical, the escape velocity will be

Two spherical bodies of mass M and 5M and radii R and 2R respectively are released in free space with initial separation between their centres equal to 12R. If they attract each other due to gravitational force only, then the distance covered by the smaller body just before collision is

The time period of a satellite of earth is 5 hour. If the separation between the earth and the satellite is increased to 4 times the previous value, the new time period will become

The escape velocity of a body depends upon mass as

Describe briefly Ultraviolet B

Describe briefly Catalytic converter

Describe briefly Greenhouse gases

What initiatives were taken for reducing vehicular air pollution in Delhi? Has air quality improved in Delhi?

Describe briefly Municipal solid wastes

Describe briefly Defunct ships and e-wastes

Describe briefly Radioactive wastes

What measures, as an individual, you would take to reduce environmental pollution?

Discuss the role of women and communities in protection and conservation of forests.

Why ozone hole forms over Antarctica? How will enhanced ultraviolet Radiations affect us?

Write critical notes on the following:

(a) Eutrophication

(b) Biological magnification

(c) Groundwater depletion and ways for its replenishment