photoelectric effect
thermionic emission
field emission
secondary emission
radioactive emission
Correct answer is B
The process by which free electrons are emitted from the surface of a metal when external heat energy is applied is called thermionic emission.
has three pro tons and two neutrons
has two protons and one neutron
has two protons and three neutrons
has one proton and two neutrons
cannot exist because it has the same mass number as tritium
Correct answer is E
No explanation has been provided for this answer.
Bqv
Bq\(\frac{v}{m}\)
Bqvm
mv\(\frac{B}{q}\)
\(\frac{mv}{Bq}\)
Correct answer is A
The formula for Force on the particle is Bqv.
In the AC circuit diagram above, the resonance frequency is
5000π Hz
2500π Hz
5000/π Hz
2500/π Hz
Correct answer is D
No explanation has been provided for this answer.
The total resistance measured at PQ in the diagram above is
18.0Ω
11.0Ω
4.0Ω
2.0Ω
Correct answer is C
The three 2 ohms are in series, therefore the total resistance is
\(R=R_1+R_2+R_3\)
\(R_ {total} =2+2+2= 6\) ohms.
resketching circuit;
6 ohms is used to replace the three 2 ohms which is therefore placed by the 3 ohms resistor.
The 3 ohms and 6 ohms resistors are in parallel, so the combined resistance is
\(R=\frac{R_1xR_2}{R_1+R_2}\)
\(R= \frac{3×6}{3+6}\)
\(R=\frac{18}{9}=2\) ohms.
Resketching circuit:
The 2 ohms is used to replace the 3 ohms and 6 ohms laying side-by-side.
Therefore, the 3 resistors (1 ohm, 1 ohm, and 2 ohms) are in series.
Thus, the total resistance is
\(R= (R_1+R_2+R_3)\)
\(R_{total} =1+1+2=4\) ohms.
Therefore, the total resistance measured at PQ is 4 ohms.
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