tape measure?
It depends on what kind of reading you want. An electrician will usually carry around a multimeter which can measure voltage, current, and resistance. Another piece of equipment that can "determine the presence of electric charge" would be a Electromagnetic Field (EMF) detector, since all electrical appliances/wires produce an electromagnetic field. There could be others, but those are the two I'm aware of.
Because an angle is a degree. It would be pretty silly to measure them in, say, horsepower, no?
The same way you measure a TV screen, diagonally (any corner to opposite corner).
direction of flow
"voltmeter"
You can measure the emf of a cell by using a voltmeter, as this draws current from a cell. You can use the voltage, the emf, and the load resistance to determine the internal resistance of the cell.
To measure the total emf simply connect the battery and voltmeter with the right terminals , but to measure the terminal potential difference which is less than the emf the voltmeter is connected in parallel with the battery
Volts are the measure of Eletro motive force. (EMF)
because voltmeter is used to measure the voltage
you can, but you will not get accurate answer as voltmeter consumes some current. so, potentiometer is used instead to measure emf ---- the potentiometer must be set to the expected emf from the cell before you put the zero detector in circuit if its set too high it will charge the cell too low it will load the cell perhaps if you dont know the voltage of the cell before you measure it you should get a hi impedance voltmeter(electrometer) to set the potentiometer as close as you can manage before you connect the zero detector
EMF stands for "electromotive force" and is (more or less) a synonym for voltage. Despite the name, it's not really a "force" in the physical sense (EMF is measured in, unsurprisingly, volts, while forces are measured in newtons), and is more properly referred to as a potential. See the related link for more details.
EMF (E''electromotive Force'') is another term for Volts, hence the E in electronic formulas and EMF is measured with a volt meter. A potentiometer is not a meter at all, it is a variable resistor
EMF (Volts) Resistance (Ohms), and most of the time, Current (Amperes, or more likely, mili Amperes)
emf in volts
Bcoz the emf which is to be measured is less than emf of driving cell....
yes indused emf is also called motional emf. If an open coil is subjected to a variable magnetic field, at the ends of the coil a potential difference is induced which is called induced emf. If a coil is connected to an emf source and switched on, the rising current will produced an variable magnetic field which in turn produces an emf. It is called back emf.