Current Electricity

A galvanometer has a resistance . A resistance of is connected parallel to it. Fraction of the total current flowing through galvanometer is

When a metal conductor connected to the left gap of a meter bridge is heated, the balancing point

To convert a moving coil galvanometer into a voltmeter

Kirchhoff's second law for the analysis of circuit is based on

The resistance of an ideal voltmeter is

When the cold and hot junctions of a thermocouple are interchanged, the thermo emf

Heater coil takes second to boil certain quantity of water. Heater coil takes second to boil same quantity of water. If and are connected in series, the time taken to boil the same quantity of water by the combination is

The steady state current through the battery in the circuit given below is

Kirchhoff's law for analysis of current at a junction in a circuit is based on

Magnitude of drift velocity per unit electric field is

Which of the following is the correct Kirchhoff's loop rule?

Consider a copper wire of length , cross-sectional area . It has number of free electrons per unit volume. Which of the following is the correct expression of drift velocity of the electrons when the wire carries a steady current ?

cells of emf each having internal resistance of ohm are connected to an external resistance of ohms . To get maximum current

Consider the two cells having emf and connected as shown in the figure. A potentiometer is used to measure potential difference between and and the balancing length of the potentiometer wire is . Same potentiometer is then used to measure potential difference between and and the balancing length is . Then, the ratio is

A metallic wire of cross sectional area carries a current of . If charge carriers flow across the wire per unit volume, then their drift velocity in is

In a potentiometer, auniform potential gradient of is maintained across its wire. The potential difference across two points on the wire located at and is

The resistance of a conductor does not depend on

The resistance of the platinum wire of a platinum resistance thermometer at the ice point is and at steam point is . When the thermometer is inserted in a hot bath, the resistance of the platinum wire will be . Calculate the temperature of the bath.

The device or substances which do not obey Ohm?s law is/are

For a copper block, find the electric field which can give on an average energy to a conduction electron. (The mean free path of conduction electrons in copper is given as )