Physics – Class 12 Practice Test 3

1. What is the SI unit of current?

Coulomb (C)

Ampere (A)

Farad (F)

Newton (N)

2. Identify the wrong statement describing the color code for carbon resistors.

The first band indicates the first significant figure

The third band indicates the third significant figure

The second band indicates the second significant figure

The fourth band indicates the possible variation in the percent of the indicated value

3. Find the true statement.

A Van de Graff generators produces large resistance and less voltage

A Van de Graff generators produces large current and less voltage

A Van de Graff generators produces large current and large resistance

A Van de Graff generator produces large voltage and less current

4. True power of a capacitor is 1.

False

True

5. In electrolytes and ionic crystals, the current carriers are free electrons.

True

False

6. In nature, free charged particles exist in the upper strata of the environment called the stratosphere. State true or false.

True

False

7. Identify the material which is suitable for making standard resistors.

Constantan

Silver

Copper

Germanium

8. Identify the dimensional formula of electric current.

[M L³ T⁰]

[M⁰ L⁰ T⁰ A¹]

[M L² T^-3]

[M L T^-2]

9. The resistivity of ‘X’ decreases with temperature and its coefficient of resistivity is negative. Identify X.

Silicon

Silver

Copper

Nichrome

10. Give the SI unit of resistivity.

ohm metre

ohm metre²

ohm/metre²

ohm/metre