Sage-Tips

How will you convert a 1mA full scale deflection galvanometer of resistance 100 Ω into an ammeter to read upto 1 A?

Explanation: When the galvanometer is at full scale, the voltage across it is V = I × R = 1ma × 100 ohms = 100mV. If we want to set full scale to be 1A, we have to shunt the meter with a resistor to take 999mA while the meter takes 1mA so the total is the 1A.

What is the value of shunt resistance that allows 20\% of the main current through a galvanometer of 99 ohm?

Therefore, the the value of shunt resistance that allows 20\% of the main current through a galvanometer of 99 Ω​ is 24.75Ω.

How can you increase the sensitivity of the galvanometer?

So, sensitivity of the galvanometer can be increased either by increasing the number of turns (N), using strong magnets or increasing the area of the coil (A). So, the correct answer is that the sensitivity of a moving coil galvanometer can be increased by increasing the number of turns of the coil.

How much current is required for a full scale deflection in galvanometer?

Full scale deflection current for galvanometer is 1 Amp.

What is full scale of ammeter?

A typical inexpensive ammeter gives a full scale deflection (FSD) when a current of 15 mA = 0.015 A flows through it. It can be adapted to measure higher currents by connecting a small resistance (known as a “shunt”) across it.

What is the deflection of a 5 ohm miliammeter?

A miliammeter of resistance 5 ohms gives a full scale deflection for a current of 15 mA. If the milliammeter is to be used to measure currents upto 1.5 A the size of the resistance that must be attached to the milliammeter is A miliammeter of resistance 5 ohms gives a full scale deflection for a current of 15 mA.

What is the resistance of 10 ohm moving coil milliammeter?

A moving coil milliammeter having a resistance of 10 ohms gives full-scale deflection when a current of 5 mA is passed through it. If the instrument is to be used to measure current upto 1 A.

What is the resistance of a milli-Amp ammeter?

A milli-amp ammeter meter will have a higher resistance than a 1 amp ammeter or a 10 amp ammeter. The shunt resistance must be less to pass a higher current because you wish to shunt or divert more current through the shunt. Your meter needs only a small current to read full scale deflection. Lets say 0.001 Amps

What are the common errors in the use of a milliammeter?

Friction error due to Jewel and pivot suspension, temperature, aging of control springs, and permanent magnets might introduce errors. Ques.14. A moving coil milliammeter having a resistance of 10 ohms gives full-scale deflection when a current of 5 mA is passed through it.