Archives

As shown in the figure, AB is a rod of length 30 cm and area of cross section 1.0 cm² and thermal conductivity 336 SI units. The ends A and B are maintained at temperatures 20degreeC and 40degreeC , respectively. A point C of this rod is connected to a box D, containing ice at 0degreeC , through a highly conducting wire of negligible heat capacity. The rate at which ice melts in the box is (assume latent heat of fusion for ice Lf= 80 cal/g)

Fourier’s law states that the negative gradient of temperature and the time rate of heat transfer is proportional to the area at right angles of... View Article

Pressure inside two soap bubbles is 1.01 and 1.02 atmosphere. What is the ratio between their volume?

The pressure inside a bubble is greater than the pressure outside the bubble when it forms. This indicates that the pressure on the bubble's... View Article

if angle of minimum deviation of a prism is equal to refracting angle of the prism, then refractive index μ of material of prism satisfies

When the entrance and departing angles of a prism are the same, the smallest deviation m occurs. The ray of light inside the prism is parallel to... View Article

The refractive index of the material of a prism is 1.5 and its refracting angle is 6°. find the deviation produced by the prism for a small angle of incidence.

When a ray incident occurs in one medium and goes in another medium, this phenomenon is called refraction. And when a ray incident occurs at one... View Article

A moving mass of 8 kg collides elastically with a stationary mass of 2 kg.If KE be the initial kinetic energy of the moving mass, the kinetic energy left with it after the collision will be :

The linear momentum of a particle is defined as the product of the mass of the particle times the velocity of that particle. Conservation of... View Article

A bullet fired at an angle of 30 degree with the horizontal hits the ground 3.0 km away. By adjusting its angle of projection, can one hope to hit a target 5.0 km away? Assume the muzzle speed to be fixed, and neglect air resistance.

Range R of the projectile R = 3km Angle of projection, =30o Acceleration due to gravity, g = 9.8m/s2 The horizontal range for the projection... View Article

The moment of inertia of thin disc of mass m and radius r, about an axis passing through one of its diameter is given by

Moment of inertia is defined as the quantity expressed by the body resisting angular acceleration which is the sum of the product of the mass of... View Article

The velocity of light (c), acceleration due to gravity (g), and atmospheric pressure (p) are chosen a fundamental units, then the dimensions of length will be

Given: Velocity of light=C Acceleration due to gravity - g Pressure -P Let 'L' be the length. Let's assume, L = CxgyPz …eq i) Now putting... View Article

Two bodies of masses ‘m’ and ‘2m’ are moving with velocities of ‘2v’ and ‘v’ respectively. calculate the ratio of theIRR (i) momentum (ii) inertia.

(i) Inertia - Inertia depends on mass, And since the mass of the two body is the same, therefore their inertia will be in the ratio of 1 : 1... View Article

Two spheres of radii 12 cm and 16 cm have equal charge. The ratio of their energies is :

A spherical capacitor consists of a solid or hollow spherical conductor, surrounded by another hollow concentric spherical of different... View Article

In the arrangement shown in fig. the ends p and q of an unstretchable string move downwards with a uniform speed u. pulleys a and b are fixed. mass m moves upwards with a speed of

Let the speed of the block of mass M is V. The point on the thread just connected to mass M will have the same velocity. The component of... View Article

The apparent frequency of the whistle of an engine changes in the ratio 9 8 as the engine passes a stationary observer. if the velocity of sound is 340 m/s, then the velocity of engine is

Answer: 20 m/s The Doppler effect is the change in the frequency of a wave observed by an observer who is moving relative to the wave source.... View Article

In an oscillating L-C circuit, the maximum charge on the capacitor is Q . The charge on the capacitor, when the energy is stored equally between the electric and magnetic field is.

Here, the given charge on the capacitor is Q. The meaning of the charge on a capacitor, when the energy is stored equally between the electric... View Article

Position-time graph for a particle is shown in the figure. Starting from t=0, at what time t, the average velocity is zero?

We need to discover a point where total displacement equals zero in order to find the time instant when average velocity equals zero. If we look... View Article

in young’s double slit experiment, fringe width observed is β. if the frequency of the source is tripled, then new fringe width will become

The formula that relates the fringe width with the wavelength of the source is given as, ⇒β=λD/d So, we can notice that keeping the distance... View Article

A force of 5 n gives a mass m1 an acceleration of 10 m s–2 and a mass m2 an acceleration of 20 m s-2 . what acceleration would it give if both the masses were tied together?

If we consider that m1 is the mass of the first object and a1 is the acceleration due to the application of an external force of 5N, from... View Article

The north pole of a bar magnet is rapidly introduced into a solenoid at one end (say a). which of the following statements correctly depicts the phenomenon taking placea) No induced emf is developed b) The end A of the solenoid behave as south pole c) The end A of the solenoid behave as north pole d) The end A of the solenoid acquires positive potential

Answer:(c) It happens in accordance with the Lenzs law. The end A becomes north pole, to oppose the motion of the magnet. Lenz’s law states... View Article

when a copper sphere is heated, maximum percentage change will be observed in (1) radius (2) area (3) volume (4) none of these

Answer: (3) volume Change in radius =rΔr=X Change in area =Δ(4πr2/(4πr2) =Δr2/r2 = 2Δr/r =2X Change in Volume =Δ(4/3πr3/(4/3πr3)... View Article

The energy required to break one mole of Cl−Cl bonds in the Cl2 is 242 KJ mol−1 . The longest wavelength of light capable of breaking a single Cl−Cl bond is:

The amount of energy necessary to break a chemical bond between A and B AB is known as bond dissociation energy. The amount of the bond... View Article

A block of mass 2 kg is placed on the floor (μ = 0.4). a horizontal force of 7 n is applied on the block. the force of friction between the block and floor is

The mass of the block as given in the question is 2kg. The coefficient of static friction is 0.4. Force applied on the block is Fnet = 2.8N... View Article

M	T	W	T	F	S	S
					1	2
3	4	5	6	7	8	9
10	11	12	13	14	15	16
17	18	19	20	21	22	23
24	25	26	27	28	29	30
31