Ammeter MCQs
The device used to measure the electric current is called as an Ammeter. Ammeter is always connected in series with the circuit which increases the resistance of the circuit. Consequently the current in circuit decreases. This small value of current cannot be measured by MCG, so to avoid this resistance of galvanometer should be low.
An Ideal has zero resistance.
The shunted permanent magnet moving coil is called as an Ammeter. Galvanometer can be converted into an ammeter of desired range by connecting low resistance called shunt in parallel with galvanometer. The formula for the shunt required for conversion of MCG into galvanometer is given as,
Q.1) An ammeter is always connected in……across the cell.
a) Series
b) Parallel
c) Either series of parallel
d) none of these
Q.2) Resistance of an ideal ammeter is….
a) infinite
b) very high
c) zero
d) can not predicted
Q.3) Moving coil galvanometer can be converted into an ammeter by connecting….
a) high value resistance in parallel
b) small value resistance in parallel
c) high value resistance in series
d) low value resistance in series
Q.4) The function of shunt resistance for an ammeter is…..
a) to provide alternating path for current
b) to increase the sensitivity of an ammeter
c) both ‘a’ and ‘b’
d) neither ‘a’ nor ‘b’
Q.5) The working of an ammeter is based on principle……
a) electromagnetic induction
b) magnetic effect of electric current
c) heating effect of electric current
d) none of these
Q.6) The value of shunt required to convert MCG into ammeter of range 0-10 A, if resistance MCG is 60 ohm and shows full scale deflection for 5 mA.
Q.7) Which among the following is correct for an ammeter?
a) Ammeter is a direct reading instrument.
b) Ammeter is highly sensitive device.
c) Ammeter is connected in series with cell.
d) All of above.
Q.8)The ratio of shunt resistance to the resistance of galvanometer is 1:1000, the ratio of current through galvanometer to total current is……
a) 1:100
b) 1:1000
c) 1:1001
d) 1:101
Q.9) What should be current through shunt resistance if the current through galvanometer of range 5 A is 10 mA……..
a) 1.99 A
b) 2.99 A
c) 3.99 A
d) 4.99 A
Q.10) 2% of total current is required for full scale deflection of coil of ammeter, then ratio of shunt resistance to that of resistance of ammeter is….
a) 49/1
b) 1/49
c) 2/23
d) 23/2
Answers:
Q.1) a) Series
Q.2) b) small value resistance in parallel
Q.3) c) 5 A, 10 π rad/s
Q.4)c) both ‘a’ and ‘b’
Q.5) b) magnetic effect of electric current
Q.6) a)
Q.7) d) All of above.
Q.8) c) 1:1001
Q.9)d) 4.99 A
Q.10) b) 1/49
