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(SOLVED)
Note : All Answers are in red.
1. By mistake, a voltmeter is placed in series and an ammeter is parallel with a resistance in an electric circuit, with a cell in series.
which of the following is not true :
If the devices are ideal, ammeter will read zero current and voltmeter will read the emf of cell
If the devices are ideal, a large current will flow through the ammeter and it will be damaged
The main current in the circuit will be very low and practically all current will flow through the ammeter, if resistance of ammeter is much smaller than the resistance in parallel.
The devices may get damaged if emf of the cell is very high and the meters are nonideal.
2. In the figure shown each resistor is of 20 Ω and the cell has emf 10 volt with negligible internal resistance. Then rate of joule heating in the circuit is (in watts)
100/11
10000/11
11
None of these
3. Five identical resistor each of resistance 1 Ω are initially arranged as shown in the figure by clear lines. If two similar resistances are added as shown by the dashed lines then change in resistance in final and initial arrangement is
2 Ω
1 Ω
3 Ω
4 Ω
4. Four identical bulbs each rated 100 watt, 220 volts are connected across a battery as shown. The total electric power consumed by the bulbs is: 
75 watt
400 watt
300 watt
400/3 watt
5. The current i in the circuit of fig. is -
- Ans
6. Two nonideal batteries are connected in parallel. Consider the following statements (I) The equivalent emf is smaller than either of the two emfs. (II) The equivalent internal resistance is smaller than either of the two internal resistance.
Both I and II are correct
I is correct but II is wrong
II is correct but I is wrong
Each of I and II is wrong.
7. The reading of voltmeter is
50V
60 V
40V
none
8. W bulb is in series with a room heater and the combination is connected across the mains. To get max. heater output, the 50 W bulb should be replaced by
25 W
10 W
100 W
200 W
9. The current through the ammeter shown in figure is 1 A. If each of the 4Ω resistor is replaced by 2Ω resistor, the current in circuit will become nearly :
A
A
- Ans
10. A In a potentiometer wire experiment the emf of a battery in the primary circuit is 20volt and its internal resistance is 5Ω. There is a resistance box (in series with the battery and the potentiometer wire) whose resistance can be varied from 120Ω to 170Ω. Resistance of the potentiometer wire is 75Ω. The following potential differences can be measured using this potentiometer which of the following is not true.
5V
6V
7V
8V .
