In figure, when an ideal voltmeter is connected across 4000Ω resistance, it reads 30V. If the voltmeter is connected…..

Q. In figure, when an ideal voltmeter is connected across 4000Ω resistance, it reads 30V. If the voltmeter is connected across 3000Ω resistance, it will read

Current Electricity

(a) 20V

(b) 22.5V

(c) 35V

(d) 40V

Ans: (b)

Three voltmeters are connected as shown. A potential difference has been applied between A and B…..

Q. Three voltmeters are connected as shown. A potential difference has been applied between A and B. On closing the switch S , readings of voltmeters ?

Current Electricity

(a) V1 increases

(b) V1 decreases

(c) V2 and V3 both increase

(d) One of V2 and V3 increases and other decreases.

Ans: (c)

A constant 60V dc supply is connected across two resistors of resistance 400kΩ and 200kΩ. What is the reading…..

Q. A constant 60V dc supply is connected across two resistors of resistance 400kΩ and 200kΩ. What is the reading of the voltmeter, also of resistance 200kΩ, when connected across the second resistor as shown in figure?

Current Electricity

(a) 12V

(b) 15V

(c) 20V

(d) 30V

Ans: (a)

In an experiment to measure the internal resistance of a cell by a potentiometer, it is found that the balance point…..

Q. In an experiment to measure the internal resistance of a cell by a potentiometer, it is found that the balance point is at a length of 3m when the cell is shunted by a 5Ω resistance and is at a length of 3m when the cell is shunted by a 10Ω resistance, the internal resistance of the cell is then

(a) 1.5 Ω

(b) 10 Ω

(c) 15 Ω

(d) 1 Ω

Ans: (b)

A milliammeter of range 10 mA has a coil of resistance 1W. To use it as an ammeter of range 1A, the required shunt….

Q. A milliammeter of range 10 mA has a coil of resistance 1W. To use it as an ammeter of range 1A, the required shunt must have resistance of

(a) 1/101 Ω

(b) 1/100 Ω

(c) 1/99   Ω

(d) 1/9Ω

Ans: (c)