Explore topic-wise InterviewSolutions in Current Affairs.

Which statement is/are correct?

i) Physical adsorption is due to Vander Waal's forces

ii) Physical adsorption decreases at high temperature

iii) Physical adsorption is irreversible

iv) Enthalpy for a chemical adsorption is generally lesser than that of physical adsorption

What is presbyopia? Which part of the bifocal lens contains the concave and convex lens?

A boy stands between the two walls and claps his hands as shown below:

If ‘x’ is less than 60m and the time between the first and the second echo is 0.25s, then calculate the value of ‘x’. (Velocity of sound in air is 344 $m{s}^{-1}$)

A substance shows a rise in temperature of $18{}^{\circ }C$ on a celsius scale. What would be the corresponding rise in temperature on a Kelvin scale?

Identify the graph of ohmic resistors in the given figure:

Which of the following is a primary source of energy for Earth?

(a) What is wind ? What type of energy is possessed by wind ?
(b) Explain how, wind energy can be used to generate electricity. Illustrate your answer with the help of a labelled diagram.
(c) State two advantages of using wind energy for generating electricity.
(d) Mention two limitations of wind energy for generating electricity.

If the speed of a car is halved, how does its kinetic energy change?

Quality or timbre of sound is instrumental in distinguishing 2 sounds with

A student is unable to see clearly the words written on the blackboard placed at a distance of approximately 4 m from him. Name the defect of vision the boy is suffering from. Explain the method of correcting this defect. Draw ray diagram for the:

Consider a heavenly body which has a mass twice that of the Earth and radius thrice that of the Earth. What will be the weight of the book on this heavenly body, if its weight on the Earth is $900N$?

Calculate the value of the linear velocity of a sphere revolving at a distance of $15cm$ from the axis of rotation, and having an angular speed of $15rad/s$.

While proving mirror formula,

How will fv/uvf = uv-uf/uvf become 1/v+1/u=1/f in the next/step.

Give any two uses of natural gas.

What function does iris do while we are sleeping?

Only one of the following applies to a concave lens. This is : (a) focal length is positive (b) image distance can be positive or negative (c) height of image can be positive or negative (d) image distance is always negative

SI unit of acceleration is:

(a) A wall reflects light and a mirror also reflects light. What difference is there in the way they reflect light ? (b) Which type of reflection of light leads to the formation of images ?

Name two human body organs where magnetism produced is significant.

A block of mass 300kg falling at 160m in 2s is used to lift a load of 900kgf. If the load rises up by 40m in same time then calculate

Which of the following is the correct order of the penetrating power of alpha ($\alpha$), beta ($\beta$) and gamma rays ($\gamma$)?

The count rate of a Geiger- Muller counter for the radiation of a radioactive material of half life of 30 minutes decreases to $5s^{-1}$ after 2 hours. The initial count rate was

the radius of curvature of a convex mirror used on a automobile is 200cm.A bus is coming behind it at a distance of 3.5m calculate (1)position (2)the size of the image relative to the bus.Also comment on the nature of image

When n resistances each of value R are connected in parallel, then resultant resistance is x. When these n resistances are connected in series, total resistance is

"A concave mirror of focal length 'f' can form a magnified erect as well as an inverted image of an object placed in front of it." Justify this statement stating the position of the object with respect to the mirror in each case for obtaining these images.

What is the reason for the defect called hypermetropia?

Which type of mirror is usually used as a rear-view mirror in motor cars ?

___________ is used to measure the amount of heat gained or lost by a substance.

The energy released in the fission of 1 kg of U-235 is equivalent to energy obtained from the burning of coal weighing ___

Potential difference is applied across the ends of a conductor. Choose the correct statement.

An irregular crystal structure reflects all the light that falls on it’s as shown in the diagram.

Which of the following statement is true?

In which of the following substances, the melting point increases with the increase in pressure.

Give four examples of radioactive substances? [2 MARKS]

Question 22
A pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water. Will the pencil appear to be bent to the same extent, if instead of water we use liquids like kerosene or turpentine. Support your answer with reason.

Suppose we take 100 mL of water which has a temperature of 348 K (75°C) and leave it in a room where the temperature is 298 K (25°C). What will happen? Is there any way of collecting all the heat lost to the environment and making the water hot once it has cooled down?

Heat can be converted to which of the following quantities?

The factors that affect the strength of a magnetic field at a point due to a straight current carrying conductor are:

If an electrical appliance of $\text{R}\Omega$ resistance draws a current $\text{I}$ for time $\text{t}$, and is connected across a battery of potential $\text{V}$, then the energy consumed by the appliance is:

How can the pollution caused by fossil fuels be decreased?

For an effective center of mass of the system of particles___

In order to obtain a magnification of, -1.5 with a concave mirror of focal length 16 cm, the object will have to be placed at a distance : (a) between 6 cm and 16 cm ,(b) between 32 cm and 16 cm (c) between 48 cm and 32 cm (d) beyond 64 cm

State which kind of vibrations (free, forced or resonant) are the following:

i) A tuning fork is struck against a rubber pad and its stem is held in hand.

ii) Two large tuning forks each of frequency 512 Hz with their stems fixed on wooden boxes are placed 1 m apart on a table. When one is set into vibrations the other too is observed to emit sound.

When a spherical mirror is held towards the sun and its sharp image is formed on a piece of carbon paper for some time, a hole is burnt in the carbon paper.

(a) What is the nature of spherical mirror?

(b) Why is a hole burnt in the carbon paper?

(c) At which point of the spherical mirror the carbon paper is placed?

(d) What name is given to the distance between spherical mirror and carbon paper?

(e) What is the advantage of using a carbon paper rather than a white paper?

Arrange in increasing order - Speed of sound in steel, in distilled water, in sea water and in oxygen.

To 50 g of water at 0⁰C is added 20 g of ice at 0⁰C. What will be the mass of water that will freeze or ice that will melt?

An electric heater of power 3 kW is used for 10 hours. How much energy does it consume? Express your answer in (i) kWh, (ii) joule.