A good way to determine the property of a substance would be it's boiling and melting point, its conductivity, and how hard or soft that substance is.
Voltage must decrease by a factor of 3 to reduce the current in the resistor by a factor of 3
Answer: Option A
<u>Explanation:</u>
According to ohms law, the voltage passed in a circuit will be directly proportional to the current flow in the circuit. So the resistance of the resistor will act as proportionality constant in ohms law. Let us consider V as original voltage producing a current I in resistor of resistance R. Then according to ohms law:
Now the revised current flow in the circuit is reduced by a factor of 3, So the new current is in the same resistance R, then the new voltage will be
So, the voltage must be reduced by a factor of 3 to reduce the current in the resistor by a factor of 3.
A can opener makes work easier by increasing force.
Explanation
Technically a can opener is a simple lever that increases the force with which we remove the cap of the can. Levers are rod shaped objects with fulcrum at one end and the length of the lever has a positive impact on the force.
considering the equation
work=force*distance
indicates that increasing the length of the lever/can opener increases the work done by it.