$CATEGORY: Science - Khan Academy/12.Electricity/12.Electricity--Resistance of a system of Resistors

//Multiple Choice

Three resistors R1\=2 Ω, R2\=4 Ω and R3\=6 Ω are connected in parallel. The equivalent resistance Req is\: {
    ~Greater than 6 Ω
    =Less than 2 Ω
    ~Between 2 Ω and 4 Ω
    ~Equal to 12 Ω
}

In a parallel circuit of three resistors, the total current is\: {
    =The sum of the currents through each resistor
    ~The same as the current through the smallest resistor
    ~The same through all resistors
    ~Always equal to the voltage
}

If three resistors are connected in parallel, the voltage across each resistor is\: {
    ~Different
    =The same as the total voltage
    ~Half of the total voltage
    ~Zero
}

The formula for calculating the total resistance Req of three resistors R1, R2 and R3 connected in parallel is\: {
    ~Req\=R1+R2+R3
    ~Req\=(R1+R2+R3)/(R1R2R3)
    =1/Req\=1/R1+1/R2+1/R3
    ~Req\=R1R2R3/(R1+R2+R3)
}

For three resistors in parallel, the equivalent resistance Req is always\: {
    ~Equal to the highest resistance
    ~Greater than the largest resistance
    =Less than the smallest resistance
    ~Equal to the sum of all resistances
}

//True or False

In a parallel circuit, the voltage across all the resistors is different. {F}

The total resistance of three resistors connected in parallel is always less than the smallest resistor. {T}

In a parallel combination, the total current is divided among the resistors. {T}

The formula R\=R1+R2+R3 is used to find the total resistance in a parallel circuit. {F}

In a parallel circuit, if one resistor is removed, the total resistance increases. {T}



//******** END **********