Recent questions in Physics

A uniform electric field of strength $\;\overrightarrow{E}\;$ exists in a region . An electron enters a point $A$ with velocity $v$ as shown . It moves through the electric field and reaches at point $B$ . Velocity of particle at $B$ is $2v$ at $30^{\circ}\;$ with x - axis . Then electric field $\;\overrightarrow{E}\;$ is

asked Feb 12, 2014 by yamini.v

1 answer

Calculate the dispersive power for crown glass from given data. $\mu_v= 1.523 $ and $\mu_R=1.5145$

asked Feb 12, 2014 by meena.p

1 answer

Find the dispersion produced by a thin prism of $18^{\circ}$ having refractive index fro red light $= 1.56$ and for violet light $=1.68$

asked Feb 12, 2014 by meena.p

1 answer

In the diagram shown , the charge +Q is fixed another charge +2q and mass M is projected from a distance R from the fixed charge . Minimum separation between the charges if the velocity becomes $\;\large\frac{1}{\sqrt{3}}\;$ times of the projected velocity , at this moment

asked Feb 12, 2014 by yamini.v

1 answer

What should be the value of refractive index n of a glass rod placed in air, so that the light entering through the flat surface of rod does not cross the curved surface of rod.

asked Feb 12, 2014 by meena.p

1 answer

Figure shows two conducting thin concentric shells of radii r and 3r . The outer shell carries charge q . Inner shell is neutral . Find the charge that will flow from inner shell to outer after the switch S is closed .

asked Feb 12, 2014 by yamini.v

1 answer

An electric dipole of dipole moment P is placed in a uniform electric field E in stable equilibrium position . It's moment of inertia about the centroidal axis is I . If it is displaced slightly from it mean position find the period of small oscillations .

asked Feb 12, 2014 by yamini.v

1 answer

What should be the value of angle $\theta$ so that light entering normally through the surface AC of a prism of refractive index $(n= \large\frac{3}{2})$ does not cross the second refracting surface AB.

asked Feb 12, 2014 by meena.p

1 answer

Find angle of refraction in a medium $(\mu =2)$ . If light is incident in vacuum making angle equal to twice the critical angle.

asked Feb 12, 2014 by meena.p

1 answer

Find maximum angle that can be made in glass medium $(\mu =1.5)$ if a light ray is refracted from glass to vacuum.

asked Feb 11, 2014 by meena.p

1 answer

Find lateral shift of light ray while is passes through a parallel glass slab of thickness 10 cm placed in air.The angle of incidence in air is $60^{\circ}$ and angle of refraction in glass is $45^{\circ}$

asked Feb 11, 2014 by meena.p

1 answer

A layer of oil 3 cm thick is floating on a layer of colored water 5 cm thick refractive index of colored water is $\large\frac{5}{3}$ and apparent depth of two liquids appears to be $\large\frac{36}{7}$cm. Then refractive index of oil:

asked Feb 11, 2014 by meena.p

1 answer

A fish in an aquarium approaches the left wall at a rate of $2.5 \;m/s$ observes a fly approaching it at $8 m/s$ If the refractive index of water is $(4/3)$ . Then the actual velocity of fly is

asked Feb 11, 2014 by meena.p

1 answer

Refractive index of glass with respect to water is $1.125$ . If the absolute refractive index of glass is $1.5 $ find the absolute refractive index of water.

asked Feb 11, 2014 by meena.p

1 answer

A ray of light is incident on a transparent glass slab of refractive index $1.62$ . If the reflected and refracted rays are mutually perpendiculars, what is angle of incidence?

asked Feb 11, 2014 by meena.p

1 answer

Light is incident formals on as oil at an incident angle of $30^{\circ}$ After moving through the oil -1, oil-2, and glass it exters water . If the refraction index of glass and water are 1.5 and 1.3 respectively . Then the angle which the ray makes with normal in water .

asked Feb 11, 2014 by meena.p

1 answer

Find speed of light in medium 'a' if speed of light in medium 'b' is $\large\frac{c}{3}$ where $c=$ Speed of light in vaccum and light refracts from medium 'a' to medium 'b' making $45^{\circ}$ and $60^{\circ}$ respective with normal.

asked Feb 11, 2014 by meena.p

1 answer

Find angle $\theta_a$ made by light ray when it gets refracted from water to air as shown .

asked Feb 11, 2014 by meena.p

1 answer

A light ray is incident on a glass sphere at angle of incidence $60^{\circ}$ as shown. then the total deviation after two refraction is :

asked Feb 11, 2014 by meena.p

1 answer

A person looks in to a spherical mirror . The size of image of his face is twice the actual size of his face. If the face is at distance 20 cm then find the radius of curvature of mirror.

asked Feb 11, 2014 by meena.p

2 answers

Find the torque due to an external uniform electric field on a dipole of dipole moment $\;\overrightarrow{P}$

asked Feb 11, 2014 by yamini.v

1 answer

An extended objected is placed perpendicular to principal axis of a concave mirror of radius of curvature 20 cm at a distance of 15 cm from pole. Find the lateral magnification produced

asked Feb 11, 2014 by meena.p

1 answer

An isolated conducting sphere whose radius $\;R=1 m \;$ has a charge $\;q=\large\frac{1}{9}\; \mu C\;$ .The energy density at the surface of the sphere is

asked Feb 11, 2014 by yamini.v

1 answer

If a luminous point is moving at a speed $V_0$ towards spherical mirror of focal length f along its axis, Find the speed of image.

asked Feb 11, 2014 by meena.p

1 answer

A thin rod of length $\large\frac{f}{3}$ is placed along optical axis a concave mirror of focal length f such that its image which is real and elongated just touches rod . calculate the magnification.

asked Feb 11, 2014 by meena.p

1 answer

The electrostatic potential due to the charge configuration at point P as shown in figure is $\;(b < < a)$

asked Feb 11, 2014 by yamini.v

1 answer

An object of length $2.5\;cm$ is placed at a $1.5\; f$ from a concave mirror where f is magnitude of focal length of mirror. The length of object is perpendicular to principal axis . Then which of following will be correct . (i) image is 5 cm long (ii) image is 10 cm long (iii) image is inverted (iv)image is erect

asked Feb 11, 2014 by meena.p

1 answer

The velocity of image will be :

asked Feb 11, 2014 by meena.p

1 answer

Where should an object be placed in from of a concave mirror of focal length 30 cm so that the image size is 5 times the object size?

asked Feb 11, 2014 by meena.p

1 answer

An object moves with 5 m/s towards right while mirror moves with 1 m/s towards the left as shown. Find velocity of image.

asked Feb 11, 2014 by meena.p

1 answer

Two plane mirrors are inclined to each other such that a ray of light incident on first mirror and parallel to second is reflected from second mirror parallel to first mirror. Find angle between two mirrors.

asked Feb 11, 2014 by meena.p

1 answer

There is a point object and a plane mirror . If the mirror is moved by 10 cm away from object , find distance which the image will move by

asked Feb 10, 2014 by meena.p

1 answer

A Point source of light B is placed at a distance L in front of centre of a mirror of width d hung vertically on a wall. A man walks in front of the mirror along a line parallel to mirror at a distance 2L from it as shown. Find greatest distance over which he can see the image of light source in mirror.

asked Feb 10, 2014 by meena.p

1 answer

The equivalent resistance between the points A and B is

asked Feb 10, 2014 by thanvigandhi_1

1 answer

For what value of $R$ will the current passing through the $4\: ohm$ resistor is zero

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Calculate the charge on the $5\mu F$ capacitor long time after assembling the circuit

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Minimum size of plane mirror, required to see full image of an observer is :

asked Feb 10, 2014 by meena.p

2 answers

The resistor which will dissipate maximum power is

asked Feb 10, 2014 by thanvigandhi_1

1 answer

In the circuit shown, if a wire is connected between points A and B, how much current will flow through it?

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Find the equivalent resistance between A and B

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Find region on Y axis in which reflected rays are present object is at A(2,0) and MN is a plane mirror as shown:

asked Feb 10, 2014 by meena.p

1 answer

The image of object A in mirror MN will be

asked Feb 10, 2014 by meena.p

1 answer

Two identical charges are placed at the two corners of an equilateral triangle . The potential energy of the system is $\;\sqcup\;.$ The work done in bringing an identical charge from infinity to the third vertex is

asked Feb 10, 2014 by yamini.v

1 answer

Current passing through the $1\: ohm$ resistor is zero. The value of $ E$ is

asked Feb 10, 2014 by thanvigandhi_1

1 answer

An ammeter and a voltmeter are joined in series to a battery. Their readings are $A$ and $V$ respectively. If a resistance is now joined in parallel with the voltmeter

asked Feb 10, 2014 by thanvigandhi_1

1 answer

$50V$ battery is supplying a current of $10A$ when connected to a resistor. If the efficiency of the battery at this current is 25%, then the internal resistance is:

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Which of these is correct for each pair of statements? \[\] Statement 1: $40W$ tube light appears brighter than a $40W$ bulb.\[\] Statement2: Light sources having same power rating appear to glow equally brightly

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Which of these is correct for each pair of statements? \[\] Statement 1: Resistance of $50W$ bulb is greater than that of a $100W$ bulb. \[\] Statement 2: Resistance of a bulb is inversely proportional to rated power.

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Which of these is correct for each pair of statements? \[\] Statement 1: The conductivity of molten electrolytes is smaller than common metallic conductors. \[\] Statement 2: Positive and negative ions flow in opposite directions.

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Which of these is correct for each pair of statements? \[\] Statement 1: When a battery is short-circuited, the terminal voltage is zero \[\] Statement 2: In the situation of a short-circuit, the current is zero

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Ask Questions, Get Answers