If the number of uranium nuclei required per hour to produce a power of 64 kW is $7.2 \times 10^{18}$, then the energy released per fission is

According to a graph drawn between the input and output voltages of a transistor connected in common emitter configuration, the region in which transistor acts as a switch is

If the energy gap of a semiconductor used for the fabrication of an LED is nearly 1.9 eV , then the color of the light emitted by the LED is

When the receiving antenna is on the ground, the range of a transmitting antenna of height 980 m is (Radius of the Earth $=6400 \mathrm{~km}$ )