Explore topic-wise InterviewSolutions in Current Affairs.

A nuclear reaction is represented by the equation :
$\underset{1}{2}H+\underset{1}{2}H⟶\underset{2}{3}He+xc+E$
(a) Name the process represented by this equation and describe what happens during this reaction.
(b) Identify the particle c and the number x of such particles produced in the reaction.
(c) What does E represent ?
(d) State two conditions under which such a reaction takes place.
(e) What type of nuclear bomb is based on similar reactions ?

The gravitational potential energy of a body of mass 'm' at the earth's surface $-mg{R}_e$. Its gravitational potential energy at a height $R_e$ from the earth's surface will be (Here $R_e$ is the radius of the earth)

A construction worker’s helmet slips and falls down when he is $78.4m$ above the ground. He hears the sound of the helmet hitting the ground $4.23$ seconds after it has slipped. Find the speed of sound in air.$(takeg=9.8m/s^2)$.

After refraction, the rays will

Calculate the height through which a body of mass 0.5 kg should be lifted if the energy spent for doing so is 1.0 joule.

Which diagram shows the resultant force correctly ?

If AB = 10 cm & DB = 40 cm (diameter). What is the radius of curvature & focal length?

The amount of work done to move a unit charge from one point to the other point is called ___.

How are waves formed ?

What is the momentum of a man of mass $100\text{kg}$ when he walks with a uniform velocity of $2{\text{m s}}^{-1}$?

The equivalent resistance of network of three 2 Ohm resistors, arranged either in parallel or series combination, can never be equal to:

How many terminals does a transistor have?

Consider the following statements:

Statement 1: No sound can be heard on the surface of the Moon.
Statement 2: Temperature of the surface of the Moon is very high and hence sound waves cannot be produced.

Choose the correct options.

In the nuclear fusion reaction ${}_1^{2}H{+}_1^{3}H{\to }_2^{4}He+n$ given that the repulsive potential energy between the two nuclei is $7.7\times {10}^{-14}J$, the temperature at which the gases must be heated to initiate the reaction is nearly [Boltzmann's constant $k=1.38\times {10}^{-23}J/K$ ]

Which type of mirror has : (a) positive focal length ? (b) negative focal length ?

The maximum displacement of the particle on either side of the equilibrium position is called ___ .

The major constituent of biogas is

A student has to connect 4 cells of 1.5V each, in-order to form a battery of voltage 6V.
Which of the following highlights the correct arrangement of cells?

A baseball is popped straight up into the air and has a hang-time of 6 s. Determine the maximum height to which the ball rises.

Match the items given in List I and List II and select the correct answer from the codes given below

:

On adding two sine waves that are exactly the same, what would be the result?

What will be the equivalent resistance between A and B?

Which type of expenditure is a non-recurring type of expenditure?

A pendulum swings through an angle of 30⁰ and describes an

arc 8.8cm in length. The length of the pendulum is

An object is placed 60 cm in front of a concave mirror. The real image formed by the mirror is located 30 cm in front of the mirror. What is the object's magnification?

Magnetic field due to a current carrying toroidal solenoid is independent of:

What is the main purpose of earthing an electical appliance ?

What is the relation between load and the effort while calculating the reciprocal of Mechanical Advantage?.

A block and tackle pulley system has five pulleys in all and is 90% efficient. Calculate the effort required to lift a load of 1000N.

An electric bulb of rating 50 W is used for 8 hours in one day. Find the number of units of energy used by the electric bulb.

1 kg of ice at $0^{o}C$ is heated at a constant rate and its temperature is recorded after every 30 s till steam is formed at ${100}^{o}C$. Draw a temperature-time graph to represent the change of phases.

Sun appears to be risen before the actual sun rise because of

The unit for measuring potential difference is:
(a) watt (b) ohm (c) volt (d) coulomb

In Fig. 7.15, A, B, C and D are the four pendulums suspended from the same elastic string XY. The lengths of pendulum A and D are equal, while the length of pendulum B is shorter and of the pendulum C is longer. The pendulum A is set into vibrations.

(a) What is your observation about the virbations of pendulum D ? (b) Give reason for your observation in part (a). (c) What type of vibrations take place in pendulums B and C ? (d) Give reason for the answer in part (c) .

The refractive index of water with respect to air is a${}^{\mu }w$ and a glass with respect to air is a${}^{\mu }g$. Express the refractive index of glass with respect to water.

What is the difference between the images produced by (i) plane mirror (ii) concave mirror (iii) convex mirror?

Explain why Sun appears white when it is overhead at noon.

Define turbine and dynamo

Define one ohm

What do we mean by saying

"Frequency of AC current is 50hz for Indian houhold"?

In what state will water be when in room temperature if it forms strong hydrogen bonds with the other water molecule???

A wave is?

The resistance of a conductor increases with-

I: Increase in length

II: Increase in volume

III: Decrease in area

The main energy transformation that occurs during charging of a battery is

What is lateral displacement? Draw a ray diagram showing the lateral displacement of a ray of light when it passes through a parallel sided glass slab.