Physics Answers

Show that 1.0 mol of ideal gas under STP (standard temperature of exactly 0 oC and pressure of exactly 1.0

atm or 101.3 kPa) occupies a volume of 22.4 L.

4. The charging battery of a parallel-plate capacitor was disconnected and a dielectric slab is inserted. What happens to the potential difference upon insertion?

a. increase by a factor of K

b. decreases by a factor of K

c. remains the same

d. cannot be determined

5. Which of the following statements is correct about the electric field of a capacitor?

a. Electric field without dielectric is stronger than the field inside the dielectric

b. Electric field without dielectric is weaker than the field inside the dielectric

c. Both a and b

d. neither a nor b

1. What is the impact of inserting dielectrics between conductor plates of a capacitor? The capacitance______.

a. decreases

b. remains the same

c. increases

d. cannot be determined

2. Which of the following arrangement of dielectric materials shows a decreasing change in the capacitance when inserted?

a. air, paper, porcelain, water

b. porcelain, air, paper, water

c. paper, porcelain, air, water

d. water, porcelain, paper, air

3. What happens to the charge of a capacitor when a dielectric material is inserted between metal plates connected to a 12-V battery?

a. increase by a factor of K

b. decreases by a factor of K

c. remains the same

d. cannot be determined

A force F=100N points 300 with respects to the x-axis. The force acts on an object of mass 5kg.

a. what is the magnitude and direction of the acceleration of that object ? [3+2 marks]

b. what are the magnitudes of the x-components of the force and the acceleration (Fx and ax)?

In the circuit shown in Fig. Q28.14, when switch S is suddenly closed, the wire L is pulled toward the lower wire carrying current I. Which (a or b) is the positive terminal of the battery? How do you know?

An ordinary loudspeaker such as that shown in Fig. 27.28 should not be placed next to a computer monitor or TV screen. Why not?

At any point in space, the electric field E is defined to be in the direction of the electric force on a positively charged particle at that point. Why don’t we similarly define the magnetic field to B to be in the direction of the magnetic force on a moving, positively charged particle?

The metal plates of Capacitor A has an area of 1 m² separated by a distance of 0.002 m. If pyrex glass is inserted in between the plates, (A) what will be the change in capacitance? (B) how much energy was stored after insertion if it has a potential difference of 12 V?

1. Dielectric Material:_____

Dielectric Constant: 1

Capacitance: 100 µF

Potential Difference: 120 V

Charge:_____

Energy:_____

2. Dielectric Material: Paper

Dielectric Constant:_____

Capacitance:_____

Potential Difference: 11 V

Charge: 6.6 × 10^–5 C

Energy:_____

1. Which of the following statement about a capacitor is correct?

a. stores chemical energy through metal plates

b. temporary storage of electric charges

c. consists of two insulators separated by a conductor

d. made up of metal plates connected by a battery

2. The metal plates of a capacitor were replaced with a bigger surface area. What will happen to it's capacitance?

a. decrease

b. remain the same

c. increase

d. cannot be determined

3. What will happen to the capacitance of a capacitor if the charge is doubled?

a. decrease

b. remain the same

c. increase

d. cannot be determined

4. What type of connection will the 2 µF obtain a greater charge?

a. series

b. parallel

c both a & b

d. neither a or b

5. What type of connection will the 2 µF obtain a greater potential difference?

a. series

b. parallel

c both a & b

d. neither a or b