10.00 Questions

QUESTION 12

A metal sphere has a charge of -6 µC. How many excess electrons are there on the sphere?

4×10-13

10×1013

4×1013

10×10-13

QUESTION 18 Two resistors 10 Ω and 5 Ω are connected in parallel across a 15 V battery. What is the potential difference across the 10 Ω resistor?

5 V

10 V

15 V

20 V

QUESTION 21 Three resistors having the same resistance value are wired in parallel. How does the equivalent resistance compare to the resistance value of a single resistor?

The equivalent resistance is thrice the value of a single resistor.

The equivalent resistance is the same as the value of a single resistor.

The equivalent resistance is one third the value of a single resistor.

The equivalent resistance is greater than the value of a single resistor.

QUESTION 22 Two resistors 3 Ω and 6 Ω are connected in parallel across a 6 V battery. What is the current flow through the 3 Ω resistor?

6 A

3 A

4 A

2 A

QUESTION 23

A 1500 W room heater is used daily for 4 hours during winter. If the cost per kWh is $0.5, what is the monthly (30 days) expense in using the room heater?

$ 9.0

$ 23

$ 90

$ 180

QUESTION 27

Which of the following is correct for a step-down transformer?

Number of turns in the primary coil is less than the number of turns in the secondary coil.

Step-down transformer increases the voltage from low value to high value. Number of turns in the primary coil is more than the number of turns in the secondary coil.

Step-down transformer is used in power station to minimize the power loss.

QUESTION 40 What is the equivalent resistance for the resistors shown in the figure? (photo attached)

QUESTION 41 When a light passes from glass to air, which of the following is correct for the path of the light?

The path of the light is bent toward the normal.

The path of the light is bent away from the normal.

The path of the light is parallel to the normal.

The path of the light is straight without any bends.

QUESTION 42

The time measured by an astronaut in the space craft to reach star B from star A is 2 years. Which of the following is correct for the time measured by an observer on the Earth's station?

1 year

2 years

less than 2 years

more than 2 years

QUESTION 43 What is nuclear fission? How do you account for the release of a large amount of energy in a nuclear fission process?

QUESTION 44 Two events that are simultaneous in one inertial frame of reference will not necessarily be simultaneous in any other inertial frame of reference. Explain.

QUESTION 45 Consider a situation where immediately after birth, twins are separated. One continues to live on earth, while the other is whisked away in a space ship at 90% of the speed of light. After 65 years they are reunited. Will they look the same? Show proof of your answer through mathematics.