Q.1
The Wheatstone bridge is used for the measurement of _________
  • a) 1ῼ to a few megaohms
  • b) 1kῼ to a few megaohms
  • c) 1Mῼ to a few gigaohms
  • d) 1mῼ to a few ohms
Q.2
The source of error in a Wheatstone bridge is due to _________
  • a) range of galvanometer used
  • b) type of the source of emf used
  • c) limiting errors of the three known resistances
  • d) balance condition
Q.3
What is the main source of error in a null detector?
  • a) lower current detection ability
  • b) insufficient sensitivity of the null detector
  • c) wiring resistance
  • d) power dissipation
Q.4
When current passes through the resistances in the Wheatstone bridge what happens?
  • a) voltage drop occurs
  • b) null detector burns
  • c) back emf is induced
  • d) temperature increases due to power dissipation
Q.5
What is the effect of the increase in temperature on the resistance elements?
  • a) directly proportional
  • b) independent
  • c) inversely proportional
  • d) changes by a factor of 10
Q.6
Heating effect in the Wheatstone bridge can be avoided by _________
  • a) using an expensive emf source
  • b) limiting current to a safe value
  • c) using heating sinks
  • d) immersing the setup in ice
Q.7
The main error when measuring low resistances is _________
  • a) power dissipation of the arms
  • b) voltage drop across the emf source
  • c) lead and contact resistance
  • d) current flowing through the circuit
Q.8
How is thermal emf generated?
  • a) when current flows
  • b) when voltage is applied
  • c) when the null detector is connected
  • d) when dissimilar metals come in contact
Q.9
Thermal emf can be prevented by _________
  • a) using more sensitive galvanometers
  • b) using similar metals
  • c) by separating the dissimilar metals
  • d) reducing the supply emf
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