A point of `gamma`-radiation has a half life of 30 minutes. The initial count rate, recorded by Geiger counter placed 2 m form the source is `360s^(-1)`. The distance between the counter and the source is altered. After 1.5 hours, the count rate recorded is `5s^(-5)`. what is the new distance between the counter and the source?

A point source of gamma - radiatonhas a half-life of 30 minutes.The intitial count rate recorded by Geiger counter placed 2 m from the source is 360 s^(-1) .The distnace between the counter and the source is altered.After 1.5 hours,the count rate recorded is 5 s^(-1) .What is th new distnace between the counter and the source?

A Geiger counter is placed at a distance of 5 m from a gamma radiation source. The half-life of gamma radiation source is 40 minutes and the count rate recorded by the Geiger counter is 400 s^(-1) . If the distance between the source and the counter is changed, then the count rate recorded will be 10s^(-1) after 2 hours. Find the new distance between the source and the counter.

A nucleus has a half-life of 30 minutes. At 3 PM its decay rate was measured as 120,000 counts/sec. What will be the decay rate at 5 PM ?

In Lloyd's interference experiment, 10 fringes occupy a space of 1.5 mm. The distance between the source and the screen is 1.25 m. If light of wavelength 6000 Å is used, find the distance of the source from the plane minor.

A counter gives a count of 320 counts/minute for a radioactive source . After 75 minutes, the counter shows a count rate of 40 counts/minute . What is the half life period of the source ?

Two point A and B are situated at distance 1 m and 2m form the source of an electrostatic field. The field at a distance x from the source is E = (5)/(x^2) . What is the potential difference between A and B?

From a point source a light falls on a spherical glass surface ( mu = 1.5 and radius of curvature = 10 cm ). The distance between point source and glass surface is 50 cm . The position of image is

From a point source a light falls on a spherical glass surface ( mu = 1.5 and radius of curvature = 10 cm ). The distance between point source and glass surface is 50 cm . The position of image is

A counter rate meter is used ot measure the activity of radioactive sample. At a certain instant the count rate was recorded as 475 counters per minute. Five minutes later, the count rate recorded was 270 counts per minute. Calculate the decay constant and half life period of the sample.