If a radioactive element with a half-life of 30 min undergoes beta decay. The fraction of the radioactive element that remains undecayed after 90 min is:
A single current-carrying loop of wire carrying current I flows in the anticlockwise direction (seen from the +z direction) and lies in the xy plane. The plot of \(\hat{j}\) component of magnetic field (\(B_y\)) at a distance a (less than radius of the coil) and on the yz plane vs z coordinate looks like:
The magnitude of magnetic induction at the mid-point O due to the current arrangement shown in the figure is:
Assertion A: If \( dQ \) and \( dW \) represent the heat supplied to the system and the work done on the system respectively, then according to the first law of thermodynamics: \[ dQ = dU - dW. \]Reason R: First law of thermodynamics is based on the law of conservation of energy.In the light of the above statements, choose the correct answer from the options given below:
Which of the following statements is not correct in the case of light emitting diodes (LEDs)?A. It is a heavily doped p-n junction. B. It emits light only when it is forward-biased. C. It emits light only when it is reverse-biased. D. The energy of the light emitted is equal to or slightly less then the energy gap of the semiconductor used.Choose the correct answer from the options given below:
In a Young’s double slit experiment, two slits are illuminated with light of wavelength \(800 \, \text{nm}\). The first minimum is detected at \(P\). The value of slit separation \(a\) is: