Four particles, each of mass M and equidistant from each other, move along a circle of radius R under the action of their mutual gravitational attraction. The speed of each particle is :?

Anonymous User Physics Gravitation and Projectile 11 Apr, 2020 64 views

A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it ? (1) A screw gauge having 100 divisions in the circular scale and pitch as 1 mm. (2) A screw gauge having 50 divisions in the circular scale and pitch as 1 mm. (3) A meter scale. (4) A vernier calliper where the 10 divisions in vernier scale matches with 9 division in main scale & main scale has 10 divisions in 1 cm.

Anonymous User Physics 10 Apr, 2020 92 views

A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 3*10^4 V/m, the charge density of the positive plate will be close to :

Anonymous User Physics Capacitors 10 Apr, 2020 63 views

The pressure that has to be applied to the ends of a steel wire of length 10 cm to keep its length constant when its temperature is raised by 100°C is :
(For steel Young’s modulus is 2 × 10^11 N m−2 and coefficient of thermal expansion is 1.1 × 10^−5 K^−1)

Anonymous User Physics Wave Optics 10 Apr, 2020 75 views

Half life of 90Sr is 6.93 years. In a child body 1 of 90Sr dopped in place of calcium, how many years will it take to reduce its concentration by 90% (Assume no involvement of Sr in metabolism).

Anonymous User Chemistry 10 Apr, 2020 67 views

Cl2 on reaction with hot & conc. NaOH gives two chlorine having products X and Y. On treatment with AgNO3, X gives precipitate. Determine average bond order of Cl and O bond in 'Y' ?

Anonymous User Chemistry 10 Apr, 2020 72 views

Shown in the figure below is a meter­bridge set up with null deflection in the galvanometer. The value of the unknown resistance R is Anonymous User Physics Current Electricity 10 Apr, 2020 95 views

A 5 V battery with internal resistance 2 and 2 V battery with internal resistance 1 are connected to a 10 resistor as shown in the figure. The current in the 10 resistor is Anonymous User Physics Current Electricity 10 Apr, 2020 58 views

Consider a block of conducting material of resistivity shown in the figure. Current I enters at A and leaves from D. We apply the superposition principle to find voltage developed between B and C. The calculation is done in the following steps:

(i) Take current I entering from A and assume it to spread over a hemispherical surface in the block.

(ii) Calculate field E(r) at distance r from A by using Ohm’s law where j is the current per unit area at r.

(iii) From the r dependence of E(r), obtain the potential V(r) at r.

(iv) Repeat (i), (ii) and (iii) for current I leaving and superpose results for A and D. For current entering at A, the electric field at a distance r from A is

Anonymous User Physics Current Electricity 10 Apr, 2020 62 views

Consider a block of conducting material of resistivity shown in the figure. Current I enters at A and leaves from D. We apply the superposition principle to find voltage developed between B and C. The calculation is done in the following steps:

(i) Take current I entering from A and assume it to spread over a hemispherical surface in the block.

(ii) Calculate field E(r) at distance r from A by using Ohm’s law where j is the current per unit area at r.

(iii) From the r dependence of E(r), obtain the potential V(r) at r.

(iv) Repeat (i), (ii) and (iii) for current I leaving and superpose results for A and D.  measured between B and C is

Anonymous User Physics Current Electricity 10 Apr, 2020 71 views

A material B has twice the specific resistance of A. A circular wire made of B has twice the diameter of a wire made of A. Then for the two wires to have the same resistance, the ratio l/ lA of their respective lengths must be

Anonymous User Physics Current Electricity 10 Apr, 2020 113 views

The resistance of a bulb filament is 100 at a temperature of 100º C. If its temperature coefficient of resistance be 0.005 per ºC, its resistance will become 200 at a temperature of

Anonymous User Physics Current Electricity 10 Apr, 2020 62 views

## The current I drawn from the 5 volt source will be The current I drawn from the 5 volt source will be Anonymous User Physics Current Electricity 10 Apr, 2020 83 views

In a Wheatstone’s bridge, three resistance P, Q and R connected in the three arms and the fourth arm is formed by two resistance S1 and S2 connected in parallel. The condition for bridge to be balanced will be

Anonymous User Physics Current Electricity 10 Apr, 2020 63 views

The Kirchhoff’s first law and second law (), where the symbols have their usual meanings, are respectively based on

Anonymous User Physics Current Electricity 10 Apr, 2020 64 views

In a potentiometer experiment, the balancing with a cell is at length 240 cm. On shunting, the cell with a resistance of , the balancing length becomes 120 cm. The internal resistance of the cell is

Anonymous User Physics Current Electricity 10 Apr, 2020 62 views

Two sources of equal emf are connected to an external resistance R. The internal resistances of the two sources are R1 and R2 (R2 > R1). If the potential difference across the source having internal resistance R2 is zero, then

Anonymous User Physics Current Electricity 10 Apr, 2020 68 views

In the circuit, the galvanometer G shows zero deflection. If the batteries A and B have negligible internal resistance, What will be the value of the resistor R? Anonymous User Physics Current Electricity 10 Apr, 2020 62 views

In a metre bridge experiment null point is obtained at 20 cm from one end of the wire when resistance X is balanced against another resistance Y. If X < Y, then where will be the new position of the null point from the same end, if one decides to balance a resistance of 4X against Y?

Anonymous User Physics Current Electricity 10 Apr, 2020 66 views

An electric current is passed through a circuit containing two wires of the same material, connected in parallel. If the lengths and radii of the wires are in the ratio of 4/3 and 2/3, then what will be the ratio of the currents passing through the wire?

Anonymous User Physics Current Electricity 10 Apr, 2020 65 views

X ml of H2 gas effuses through a hole in a container in 5 seconds. The time taken for the effusion of the same volume of the gas specified below under identical conditions is :

Anonymous User Chemistry 09 Apr, 2020 90 views

The behaviour of a real gas is usually depicted by plotting compressibility factor Z versus P at a constant temperature. At high temperature and high pressure, Z is usually more than one. This fact can be explained by van der Waals equation when

Anonymous User Chemistry 09 Apr, 2020 93 views

The velocity of electron in the ground state hydrogen atom is . Its velocity in the second orbit would be

Anonymous User Chemistry 09 Apr, 2020 90 views

An electron is moving with a kinetic energy of . What will be de Broglie wave length for this electron?

Anonymous User Chemistry 09 Apr, 2020 60 views

## The total current supplied to the circuit by the battery is The total current supplied to the circuit by the battery is Anonymous User Physics Current Electricity 08 Apr, 2020 61 views

## The total current supplied to the circuit by the battery is The total current supplied to the circuit by the battery is Anonymous User Physics Current Electricity 08 Apr, 2020 61 views

A 3 volt battery with negligible internal resistance is connected in a circuit as shown in the figure. The current I, in the circuit will be Anonymous User Physics Current Electricity 08 Apr, 2020 59 views

The length of a wire of a potentiometer is 100 cm, and the e.m.f. of its standard cell is E volt. It is employed to measure the e.m.f. of a battery whose internal resistance is If the balance point is obtained at l = 30 cm from the positive end, the e.m.f. of the battery is

Anonymous User Physics Current Electricity 08 Apr, 2020 60 views

## If equation has  roots equal in magnitude & opposite in sign, then the value of k is? If equation has  roots equal in magnitude & opposite in sign, then the value of k is?

Anonymous User Maths Quadratic Equation 07 Apr, 2020 99 views

## For the reaction are positive. The most favourable conditions for the reaction is For the reaction are positive. The most favourable conditions for the reaction is

Anonymous User Chemistry 07 Apr, 2020 55 views