The resistance of platinum wire at 0 is 22.05 and at 100 it becomes 22.70 . When the wire is heated to a temperature of t the resistance of wire becomes 24.91. The value of t is
1. 220
2. 440
3. 310
4. 550
A meter bridge is set up to determine unknown resistance x using a standard 10 resistor. The galvanometer shows the null point when the tapping key is at a 52 cm mark. End corrections are 1 cm and 2 cm respectively for end A and B. Then the value of x is:
1. 10.2
2. 10.6
3. 10.8
3. 11.1
Express which of the following setups can be used to verify Ohm’s law
(1) | |
(2) | |
(3) | |
(4) |
The equivalent resistance of the following infinite network of resistances is
(1) Less than 4 Ω
(2) 4 Ω
(3) More than 4 Ω but less than 12 Ω
(4) 12 Ω
In the given figure, the potential difference between A and B is:
1. | 0 | 2. | 5 volt |
3. | 10 volt | 4. | 15 volt |
If each resistance in the figure is 9 Ω, then the reading of the ammeter is:
1. 5 A
2. 8 A
3. 2 A
4. 9 A
In the circuit shown below, The reading of the voltmeter V is
(1) 12 V
(2) 8 V
(3) 20 V
(4) 16 V
In the circuit shown in the figure, the current flowing in 2 Ω resistance
(1) 1.4 A
(2) 1.2 A
(3) 0.4 A
(4) 1.0 A
In the given circuit, the voltmeter records 5 volts. The resistance of the voltmeter in ohms is :
(1) 200
(2) 100
(3) 10
(4) 50
In the adjoining circuit, the battery E1 has an e.m.f. of 12 volts and zero internal resistance while the battery E has an e.m.f. of 2 volts. If the galvanometer G reads zero, then the value of the resistance X in ohm is
(1) 10
(2) 100
(3) 500
(4) 200
Two identical cells send the same current in 2 Ω resistance, whether connected in series or in parallel. The internal resistance of the cell should be
(1) 1 Ω
(2) 2 Ω
(3)
(4) 2.5 Ω
Eels are able to generate current with biological cells called electroplaques. The electroplaques in an eel are arranged in 100 rows, each row stretching horizontally along the body of the fish containing 5000 electroplaques. The arrangement is suggestively shown below. Each electroplaques has an emf of 0.15 V and internal resistance of 0.25 Ω
The water surrounding the eel completes a circuit between the head and its tail. If the water surrounding it has a resistance of 500 Ω, the current an eel can produce in water is about
(1) 1.5 A
(2) 3.0 A
(3) 15 A
(4) 30 A
For measurement of potential difference, the potentiometer is preferred in comparison to the voltmeter because:
1. the potentiometer is more sensitive than the voltmeter.
2. the resistance of the potentiometer is less than
the voltmeter.
3. the potentiometer is cheaper than the voltmeter.
4. the potentiometer does not take current from the circuit.
In the diagram shown, the reading of voltmeter is 20 V and that of ammeter is 4 A. The value of R should be (consider given ammeter and voltmeter are not ideal) :
(1) Equal to 5 Ω
(2) Greater from 5 Ω
(3) Less than 5 Ω
(4) Greater or less than 5 Ω depends on the material of R
A resistance of 4 Ω and a wire of length 5 metres and resistance 5 Ω are joined in series and connected to a cell of e.m.f. 10 V and internal resistance 1 Ω. A parallel combination of two identical cells is balanced across 300 cm of the wire. The e.m.f. E of each cell is:
1. 1.5 V
2. 3.0 V
3. 0.67 V
4. 1.33 V
The potential difference across the 100Ω resistance in the following circuit is measured by a voltmeter of 900 Ω resistance. The percentage error made in reading the potential difference is :
(1)
(2) 0.1
(3) 1.0
(4) 10.0
A torch bulb rated as 4.5 W, 1.5 V is connected as shown in the figure. The e.m.f. of the cell needed to make the bulb glow at full intensity is :
(1) 4.5 V
(2) 1.5 V
(3) 2.67 V
(4) 13.5 V
In the given circuit, with a steady current, the potential drop across the capacitor must be :
(1) V
(2) V / 2
(3) V / 3
(4) 2V / 3
12 cells each having the same emf are connected in series with some cells wrongly connected. The arrangement is connected in series with an ammeter and two similar cells which are in series. Current is 3 A when cells and battery aid each other and is 2 A when cells and battery oppose each other. The number of cells wrongly connected is/are:
1. 4
2. 1
3. 3
4. 2
A potentiometer wire of length L and a resistance r are connected in series with a battery of e.m.f. and a resistance r1. An unknown e.m.f. is balanced at a length l of the potentiometer wire. The e.m.f. E will be given by
(1)
(2)
(3)Eol/L
(4)