Explanation:
The total resistance used to calculate the total resistance of the two parallel resistor is given by :
Taking reciprocal of the above equation.
We can also write the above equation as :
On simplification of above equation,
or
Hence, proved.
Answer:
d. the voltage difference between the ends of each resistor is the same.
Explanation:
A resistor is a circuit component that offers opposition to the flow of current. Resistors may be connected in series or in parallel.
Resistors in parallel are connected at common junctions. The potential difference (voltage difference between the ends of each resistor) is the same for each resistor in a parallel connection while the current across each resistor is different.
<u>Out of all given choices, the following statements are true:</u>
- An ammeter is used to measure current.
- A voltmeter is used to measure voltage.
- A voltmeter must be placed in parallel with a resistor to measure the voltage across the resistor.
Options A, E, and F
<u>Explanation:</u>
An instrument by which the current in a circuit is measured is called ammeter whereas an instrument in which voltage is measured in a circuit is called a voltmeter . The ammeter is placed in series with the resistor while the voltmeter is placed in parallel with the resistor.
For the option B, since the ammeter must be placed in series with the resistor to measure current, it is false. Option C is false because an ammeter has zero internal resistance. Option D is also false because a voltmeter has a high internal resistance and is actually infinite.
Answer:
A
Explanation:
Electromagnet: It is a temporary magnet. It consists of wrapping coils around iron core and the power source. When the current passes through the coils around the iron core then it will get magnetized. The domains of the electromagnet gets aligned.
As long as the current passes through it, it will get magnetized. It will loose its magnetism easily when the power is switched off.
In the electromagnet, the strength of the magnetism can be increased or decreased. The poles of the electromagnet are not fixed.
