On her vacations,Veena visits four cities ($A, B, C$,and $D$) in a random order. What is the probability that she visits $A$ before $B$?

Find the value of the current through the $2\,\Omega$ resistance for the given circuit. (in $,A$)

Temperature of cold junction in a thermocouple is $10^{\circ} C$ and neutral temperature is $270^{\circ} C$,then the temperature of inversion is (in $^{\circ} C$)

In a transistor circuit,when the base current is increased by $50 \mu A$ keeping the collector voltage fixed at $2 \ V$,the collector current increases by $1 \ mA$. The current gain of the transistor is

The circuit shown contains a $12 \ V$ battery,a $4 \ \Omega$ resistor,and two branches in parallel,each containing an ideal diode and a resistor. Branch $1$ has diode $D_1$ and a $3 \ \Omega$ resistor,while branch $2$ has diode $D_2$ and a $2 \ \Omega$ resistor. Determine the total current flowing in the circuit. (in $A$)

Which of the following has the lowest melting point?