Which of the following is not a type of energy source?
Answer: Option B
Explanation:
Rheostat is a variable resistor. It has three terminals. 2 fixed terminals and one variable terminal to vary the resistance. It can be kept in either cut in or cut out position. If kept in cut out position it offers zero resistance. When kept in cut in position it provides the full resistance. The cut in nd cut out position is kept using the third terminal. Kindly see the pic of a rheostant you ll understand better.
The maximum resistance value for a brown, red, yellow, gold resistor is
Answer: Option A
Brown =1 red=2 yellow=10^4 Gold=5%, So=120000+5%, 120000+6000, =126000.
The minimum resistance value for a blue, gray, red, silver resistor is
Because of 10% tolerance(last color silver), this resistance may vary 10% of 6800.
Minimum resistance value = 6800 - 680 = 6120
Maximum resistance value = 6800 + 680 = 7480
Current flows in a circuit when
When circuit is open current does not flow, When switch is closed in any circuit it acts as a closed circuit so current flows only in a closed circuit
Materials with lots of free electrons are called
Conductors have more free electrons that are not aligned, once the voltage is applied they start conducting, but semiconductors don conducts til the threshold voltage is overcome. So conductors have more free electrons than others.
