Question

Which of the following can be used in a tester along
with a battery to detect a weak current in the circuit?
(1) LED only
(2) A coil wound over a compass needle only
(3) Bulb of 100 W only
(4) Either LED or a coil wound over a compass needle

Answer 1

LED and coil wound over a ‘compass needle’ can be used in a ‘tester along with a battery’ to detect a ‘weak current’ in the ‘circuit’.

Explanation:

• To demonstrate a weak current a detector may be such that it can produce the change even in a small amount of charge.

• So to glow a 100 W bulb, a huge amount of current is needed. So it is inappropriate for this purpose.  

• A wire carry a charge produces a magnetic field. Hence a coil can detect such change. Again led also work in very low current even in form of battery.  

Learn more about LED

What led to a rapid increase in the demand for food grains in 1789?

https://brainly.in/question/1191440

State the factors that have led to the overuse of land resources.

https://brainly.in/question/453290

Answer 2

Answer:

Weak electric current flowing through a liquid can also be detected by using a compass. We take out the cardboard tray from the inside of a discarded matchbox and place a small compass inside this cardboard tray. Hope it will help you.29-Sep-2021

Explanation:

please follow and brainliest answer