Chapter 9. Current Electricity
IMPORTANT QUESTIONS
1) What is ideal requirement of ammeter? How it is achieved practically?
2) Explain Seebeck effect.
3) With the help of a neat diagram, obtain balance condition of Whetstone's
network.
4) Define e.m.f. of a cell. Can a voltmeter measure E M.F.? Explain.
5) Explain the principle of potentiometer with experimental setup.
6) State Kirchhoff's current and voltage laws.
7) Draw a neat and labelled diagram for a setup of G by Kelvin’s method.
8) What is ideal requirement of ammeter? How it is achieved practically?
9) A potentiometer wire has a length of 4 meters and resistance of 10 ohms. The
wire is connected to a battery of e.m.f. 4 volts and internal resistance 2 ohms. Find
the P.D. per cm of the wire. Also find balancing length corresponding to cell of
e.m.f. 1.5 volt.
10) A P.D. of 0.75 V applied across a galvanometer causes a current of 15 mA to
pass through it. How will you convert it into an ammeter to measure currents up to
25 A?
11) In a meter bridge experiment with resistance X in left gap and 60 Ω in right
gap null point is obtained at l cm. If X is shunted by X, what should be resistance
in right gap to get same null point?
12) A galvanometer of resistance 50 ohm has a sensitivity of 10 div/mA. What is
the
shunt resistance required to change the sensitivity to 2 div/mA?
13) A voltmeter has a resistance 100 Ω. What will be its reading, when it is
connected across a cell of EMF 2 V and internal resistance 20 Ω?
14) A potentiometer wire has a length of 1.5 m and resistance 10 Ω. It is connected
in series with the cell of EMF 4 V and internal resistance 5 Ω. Calculate the
potential drop per centimetre of the wire.
15) When two cells of EMFs E1 and E2 are connected in series so as to assist each
other, their balancing length on a potentiometer is found to be 2.7 m. When the
cells are connected in series so as to oppose each other, the balancing length is
found to be 0.3 m. Compare the EMFs of the two cells.
IMPORTANT QUESTIONS
1) What is ideal requirement of ammeter? How it is achieved practically?
2) Explain Seebeck effect.
3) With the help of a neat diagram, obtain balance condition of Whetstone's
network.
4) Define e.m.f. of a cell. Can a voltmeter measure E M.F.? Explain.
5) Explain the principle of potentiometer with experimental setup.
6) State Kirchhoff's current and voltage laws.
7) Draw a neat and labelled diagram for a setup of G by Kelvin’s method.
8) What is ideal requirement of ammeter? How it is achieved practically?
9) A potentiometer wire has a length of 4 meters and resistance of 10 ohms. The
wire is connected to a battery of e.m.f. 4 volts and internal resistance 2 ohms. Find
the P.D. per cm of the wire. Also find balancing length corresponding to cell of
e.m.f. 1.5 volt.
10) A P.D. of 0.75 V applied across a galvanometer causes a current of 15 mA to
pass through it. How will you convert it into an ammeter to measure currents up to
25 A?
11) In a meter bridge experiment with resistance X in left gap and 60 Ω in right
gap null point is obtained at l cm. If X is shunted by X, what should be resistance
in right gap to get same null point?
12) A galvanometer of resistance 50 ohm has a sensitivity of 10 div/mA. What is
the
shunt resistance required to change the sensitivity to 2 div/mA?
13) A voltmeter has a resistance 100 Ω. What will be its reading, when it is
connected across a cell of EMF 2 V and internal resistance 20 Ω?
14) A potentiometer wire has a length of 1.5 m and resistance 10 Ω. It is connected
in series with the cell of EMF 4 V and internal resistance 5 Ω. Calculate the
potential drop per centimetre of the wire.
15) When two cells of EMFs E1 and E2 are connected in series so as to assist each
other, their balancing length on a potentiometer is found to be 2.7 m. When the
cells are connected in series so as to oppose each other, the balancing length is
found to be 0.3 m. Compare the EMFs of the two cells.
