The average energy of a neutron produced in the fission of ${ }_{92}^{235} \mathrm{U}$ is

If $96.875 \%$ of a radioactive substance decays in 10 days, then the half life of the substance is (in days)

The power gain and voltage gain of a transistor connected in common emitter configuration are 1800 and 60 respectively. If the change in the emitter current is 0.62 mA , then the change in the collector current is

Six logic gates are connected as shown in the figure. The values of $y_1, y_2$ and $y_3$ respectively are