What will be the probability that at least one of the event occurs for three events A, B and C, P(Exactly one of A or B occurs) = P(Exactly one of B or C occurs) = P(Exactly one of C or A occurs) = 1/4 and P(All the three events occur simultaneously) = 1/16?

Anshul Kumar Singh Maths 02 Sep, 2017 1 Answer 987 views


What will be the beat frequency of the resulting signal in Hz if A stationary source emits sound of frequency f = 492 Hz. The sound is reflected by a large car approaching the source with a speed of 2 m/s. The reflected signal is received by the soruce and superposed with the original (Given that the speed of sound in air is 330 m/s and the car reflects the sound at the frequency it has received)?

Preeti Rai Physics 31 Aug, 2017 3 Answer 219 views






What will be the value of T if A copper ball of mass 100 gm is at a temperature T. It is dropped in a copper calorimeter of mass 100 gm,filled with 170 gm of water at room temperature. Subsequently, the temperature of the system is found to be 750C. T is given by: (Given : room temperature = 300C, specific heat of copper = 0.1 cal/gm0C)?

Anshul Kumar Singh Physics 26 Aug, 2017 1 Answer 387 views


A compound ‘X’ reacts with a compound ‘Y’, to produce a colourless and odourless gas. The gas turns lime water milky. When ‘X’ reacts with methanol in the presences of concentrated H2SO4, a sweet smelling substance is produced. The molecular formula of the compound ‘X’

Anshul Kumar Singh Chemistry 09 Aug, 2017 0 Answer 510 views


The following observations were taken for determining surface tension T of water by capillary method: diameter of capillary, D = 1.25 *10^-2m rise of water, h = 1.45 *10^2m Using g = 9.80 m/s2 and the simplified relation T = (rhg*10^)/2 N/ m, the possible error in surface tension is closest to?

Rahul Kumar Physics 04 Aug, 2017 1 Answer 213 views



A rocket is launched normal to the surface of earth, away from the Sun, along the line joining the Sun and the Earth. The Sun is 3 *10^5 times heavier than the Earth and is at a distance 2.5 *10^4 times larger than the radius of the Earth. The escape velocity from Earth’s gravitational field is ve = 11.2 km /s The minimum initial (vs) required for the rocket to be able to leave the Sun-earth system is closest to(Ignore the rotation and revolution of the Earth and the presence of any other planet).

Rahul Kumar Physics 30 Jul, 2017 1 Answer 316 views

An electron in a hydrogen atom undergoes a transition from an orbit with quantum numebr ni to another with quantum number nf. Vi and Vf are respectively the initial and final potential energies of the electon. If vi/ vf =6.25, Then what is smallest possible nf is

Preeti Rai Chemistry 29 Jul, 2017 1 Answer 441 views



A crystalline solid of a pure substance has a face-centred cubic structure with a cell edge of 400 pm. If the density of the substance in the crystal is 8 g cm-3, then the number of atoms present in 256 g of the crystal is N × 1024. The value of N?

Rahul Kumar Chemistry 28 Jul, 2017 1 Answer 1053 views







Two balls are dropped to the ground from different heights. One ball is dropped 2s after the other but they both strike the ground at the same time. If the first ball takes 5s to reach the ground, then the difference in initial heights is (g = 10 ms–2) 40

Preeti Rai Physics 23 Jul, 2017 1 Answer 4491 views
















Mr. Sharma and Mr. Arora are family friends and they decided to go for a trip with family . For the trio they reserved their rail tickets . Mr. Arora has not taken a half ticket for his child who is 6 years old where as Mr, Sharma has taken half tickets for his two children who are 6 year and 8.5 year.A railway half ticket costs half of the full fare but the reservation charges are the same as on a FULL TICKET. MR AND MRS ARORA PAID 1700,WHILE MR AND MRS SHARMA PAID 2700. Find the full share of one ticket and reservation charges per ticket.

Ashish Maurya Maths 07 Jul, 2017 1 Answer 1846 views