Chapter 6: Current Electricity — Online MCQ Test
PHYSICS · CLASS 12 INTERMEDIATE 2 YEAR · Telangana State Board
Practice Chapter 6: Current Electricity with a free chapter-wise online MCQ test.
This chapter covers: This chapter covers electric current Ohm Law drift velocity resistance temperature dependence Kirchhoff laws Wheatstone bridge meter bridge and potentiometer applications..
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 6: Current Electricity — Important Questions & Answers
What is the SI unit of electric current?
- A. Volt
- B. Ampere
- C. Ohm
- D. Coulomb
Answer: B. Ampere
Electric current is measured in ampere (A), which is the SI unit of current.
Electric current is measured in ampere (A), which is the SI unit of current.
Ohm's law states that for a conductor at constant temperature, current is directly proportional to:
- A. Resistance
- B. Potential difference
- C. Power
- D. Charge density
Answer: B. Potential difference
According to Ohm's law, V = IR, so current is directly proportional to potential difference when temperature remains constant.
According to Ohm's law, V = IR, so current is directly proportional to potential difference when temperature remains constant.
If the drift velocity of electrons in a conductor increases, the current will:
- A. Decrease
- B. Remain zero
- C. Increase
- D. Become alternating
Answer: C. Increase
Current is directly proportional to drift velocity for a given conductor, so increasing drift velocity increases current.
Current is directly proportional to drift velocity for a given conductor, so increasing drift velocity increases current.
Two wires of the same material and length have radii r and 2r. The ratio of their resistances R1 : R2 is:
- A. 1 : 2
- B. 2 : 1
- C. 4 : 1
- D. 1 : 4
Answer: C. 4 : 1
Resistance is inversely proportional to cross-sectional area, and area varies as r^2. So doubling the radius makes the resistance one-fourth.
Resistance is inversely proportional to cross-sectional area, and area varies as r^2. So doubling the radius makes the resistance one-fourth.
Which change will increase the sensitivity of a potentiometer?
- A. Increase current through the potentiometer wire
- B. Use a shorter potentiometer wire
- C. Reduce the potential gradient along the wire
- D. Increase the resistance of the galvanometer branch
Answer: C. Reduce the potential gradient along the wire
Lower potential gradient gives a larger balancing length for a given potential difference, making the potentiometer more sensitive.
Lower potential gradient gives a larger balancing length for a given potential difference, making the potentiometer more sensitive.