Physics paper 1 (set a)

There is a repulsive force between two charged object when:

• The charges are of opposite sign

• They have the same proton number

• Charge are of same sign

• They have the same electron number

Which of the following statement about coulomb force is true?

• Attractive force if both charges have the same sign.

• Force is directly proportional to the product of the charge

• Force is directly proportional to the masses of the charges

• Force is directly proportional to the square of tue separation distance of the two charges

the position of two particles X and Y of charges -q and -2q respectively are fixed. Which of the following figures correctly shows the direction and magnitude of forces on the particles?

• 
• 
• 
• 

Where is the direction of the electric field at the midpoint location between the charges +Q1 and negative -Q2?

• Directed towards +Q1

• Directed towards -Q2

• Not possible to determine its direction since the value of charge is not given

• Undetermined since the resultant electric field is zero

Two parallel plate capacitor are identical in every respect except that one has twice the plate area of the other. If the smaller capacitor has capacitance C, the larger one has capacitance?

• C/2

• C

• 2C

• 4C

A parallel-plate capacitor has a capacitance of C. If the area of the plates is doubled and the distance between the plates is halved, what is the new capacitance?

• C/4

• C/2

• 2C

• 4C

Which of the following statement will necessarily increase the capacitance of a capacitor?

• Decreasing the charge of the plates

• Increasing the charge on the plates

• Placing dielectric between the plates

• Increasing the potential difference between the plates

What is the unit of capacitance?

• F

• C

• I

• V

Which statement is FALSE about electricity?

• Electric current is defined as the rate charge flow

• Resistance increases when temperature increases

• Electric current decreases when resistance increases

• Resistivity increases when length of conductor increases

If R1<R2<R3<R4 are connected in parallel in a circuit, which one has the highest current

• R1

• R2

• R3

• R4