Explore topic-wise InterviewSolutions in Current Affairs.

Consider the following statements and choose the correct option.

1. Magnetic field lines form closed loops.

2. No two field lines intersect

Answer the following.

Name disease caused due to water pollution.

In order to rotate a bar pivoted at its mid point, we need to apply

A coil of resistance $400\Omega$ is placed in a magnetic field. If the magnetic flux $\varphi$ $\left(Wb\right)$ linked with the coil varies with time $t$ (sec) as $\varphi =50t^2+4$, the current in the coil at $t=2sec$ is

A ray of light travelling in air goes into water. The angle of refraction will be :

(a) ${90}^{\circ }$ (b) smaller than the angle of incidence (c) it goes along the normal (d) greater than the angle of incidence

A rod of length $L$ and resistance $r$ rotates about one end with angular velocity $\omega$ as shown in the figure, its other end touches a conducting ring of negligible resistance. A resistance $R$ is connected between the centre and periphery. There is a uniform magnetic field $B$ directed as shown in the figure. Find the current in resistance $R$.

In the figure shown, the ammeter reading will be independent of $R_2$ when

The pressure of real gas is less than the pressure of an ideal gas because of:

V/m is the unit of:

a)potential

b)electric potential energy

c)electric current

d)electric field intensity

The angle between the emergent ray and incident ray when the light goes from air to glass slab is ____

In which of the following cases light bends towards the normal?

A telescope has an objective lens of $20\text{cm}$ diameter and is situated at a distance of $2\text{km}$ from two objects. The minimum distance between the two objects, which can be resolved by the telescope, when mean wavelength of light is $6000\text{Å}$, is order of

The principle of Ocean thermal energy conversion is

By what name is the physical quantity coulomb/second called ?

When light of wavelength $\lambda$ is incident on an equilateral prism kept in its minimum deviation position, it is found that the angle of deviation equals the angle of the prism itself. The refractive index of the material of the prism for the wavelength $\lambda$ is, then

Why does the eye need to change the focal length of the eye lens?

Find the focal length of the lens shown in figure. The radius of curvature is $R=10\text{cm}$ and the refractive index of material of the lens is $\frac{3}{2}$.

If the image formed by a convex lens is of the same size as that of the object, what is the position of the image with respect to the lens ?

Which of the following are the properties of ultraviolet radiations?

The magnetic field lines :

(a) intersect at right angles to one another

(b) intersect at an angle of ${45}^o$ to each other

(c) do not cross one another

(d) cross at an angle of ${60}^o$ to one another

A ray of light passes through $4$ transparent media with refractive indices ${\mu }_1,{\mu }_2,{\mu }_3$ and ${\mu }_4$ as shown. The surface of all media are parallel. If the emergent ray $\text{CD}$ is parallel to the incident ray $\text{AB}$, we must have

A star sometimes appears brighter and some other times fainter. What is this effect called? State the reason for this effect.

In the circuit shown, the variable resistance is so adjusted that the ammeter reading is the same in both the positions 1 and 2 of the key. The reading of the ammeter is $2\text{A}$. If $E=10\text{V}$, then $X$ is

If $F_1$ and $F_2$ represents the foci of the lens, then at which point will the light rays meet?

In the circuit shown in figure, switch remains closed for long time. It is opened at time $t=0$. Match the following two columns at $t=\ln 2$ second.



$\begin{array}{cc}\text{Column\_I}& \text{Column-II}\\ \text{(a) Potential difference across inductor}& \text{(p) 9 V}\\ \text{(b) Potential difference across}3\Omega \text{resistance}& \text{(q) 4.5 V}\\ \text{(c) Potential difference across}6\Omega \text{resistance}& \text{(r) 6 V}\\ \text{(d) Potential difference between points b and c}& \text{(s) None of these}\end{array}$

Two stationary sources each emit waves of wavelength $\lambda$. An observer moves from one source to another with velocity $u$. Then, the number of beats per second heard by the observer is:



[Assume, medium is stationary ; the source and the observer are collinear]

A coaxial cable contains an insulating material of conductivity $\sigma$ .If the radius of the central wire is a and that of the sheet is b, then the conductance per unit length is

What is the nature of image formed in:

a. Concave lens

b. Convex lens

Also, give one use of each lens.

What is Brewster's angle for air to glass transition? (Refractive index of glass 1.43)

Two rods with the same dimensions have thermal conductivities in the ratio $1:2$. They are arranged between heat reservoirs with the same temperature difference, in two different configurations, A and B. The rates of heat flow in A and B are $I_A$ and $I_B$ respectively. The ratio $\frac{I_A}{I_B}$ is equal to