Ohm's law is valid only when

1

(a)

Graph between V and I is a straight line

(b)

Temperature increases

(c)

Temperature decreases

(d)

Temperature remains constant.

If I is the current through a wire and 1 is the charge of electron, then no. of electrons in t seconds will be

1

(a)

1/It

(b)

It/1

(c)

\(\frac { 11 }{ t } \)

(d)

It1

Electrical resistivity of a given metallic wire depends upon

1

(a)

its length

(b)

its thickness

(c)

its shape

(d)

nature of the material

A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be roughly

1

(a)

10²⁰

(b)

10¹⁶

(c)

10¹⁸

(d)

10²³

What is the maximum resistance while can be made using five resistors each of 1/5\(\Omega \).

1

(a)

1/5\(\Omega \)

(b)

10\(\Omega \)

(c)

1/10\(\Omega \)

(d)

25\(\Omega \)

What is meant by the statement, "Potential difference between points A and B in an electric field is 1 volt"?

1

(a)

It means that 1 joule of work will be done in order to move 1 coulomb of charge from point A to B.

Why is the series arrangement not used for connecting domestic electric appliances in a circuit?

1

(a)

In a domestic circuit, parallel connection of devices is preferable for several reasons:
a. In series connection, if one of the devices is defective, if one of the devices is defective,     then the current of the entire circuit is cut off. As a result, all the devices stop working. In parallel connection, even if one device is defective, the others continue working.
b. In series connection, selective operation of devices is not possible, but this is not so in the case of parallel connection.
c. In series connection, the same current passes through all the devices, regardless of the fact that different devices require differnt values of currect to operate. In parallel connection, different values of currect can be obtained for different devices according to their requirements.

What is an ammeter?

1

(a)

A measuring instrument used to measure electric current.

Give the S.I. unit of electric current?

1

(a)

Ampere (A)

How is ammeter and voltmeter connected in a circuit?

1

(a)

Ammeter is connected in series and voltmeter is connected in parallel.