alleryThe SI unit of current density is:
- A
- A m²
- A m⁻²
- A m⁻¹
Show answer and solution
Correct answer: C. A m⁻²
Current density j = I/A, so its SI unit is ampere per square metre, A m⁻².
NEET UG Current Electricity — practice questions — page 2
Explore 163 free Current Electricity questions in NEET UG Physics. Open each question or exercise to read its content, reference answers and available explanation.
Practise Current Electricity with Quill →Current Electricity questions and exercises with answers
Showing questions 31–60 of 163.
The SI unit of current density is:Read the answer and worked solution →For a uniform wire of resistance R = ρl/A, the resistivity ρ depends on:Read the answer and worked solution →The power dissipated in a resistor of resistance R carrying a steady current I is:Read the answer and worked solution →The emf of a cell is equal to the potential difference across its terminals when:Read the answer and worked solution →Three resistors of 2 Ω, 3 Ω and 5 Ω are connected in series. The equivalent resistance is:Read the answer and worked solution →Two 6 Ω resistors are connected in parallel. Their equivalent resistance is:Read the answer and worked solution →A cell of emf 2 V and internal resistance 0.1 Ω is connected across a 3.9 Ω resistor. The current in the circuit is:Read the answer and worked solution →A cell of emf 2 V and internal resistance 0.1 Ω drives a current of 0.5 A. Its terminal potential difference is:Read the answer and worked solution →In a metallic wire of fixed n and area A, if the current is doubled, the electron drift speed:Read the answer and worked solution →A wire is stretched to twice its original length while keeping its volume constant. Its new resistance is:Read the answer and worked solution →Two bulbs rated 100 W and 60 W are designed for the same supply voltage. Compared with the 60 W bulb, the 100 W bulb has:Read the answer and worked solution →A platinum resistance thermometer reads 5.00 Ω at 0°C and 5.23 Ω at 100°C. When its resistance is 5.795 Ω, the temperature is about:Read the answer and worked solution →The heat produced in a 5 Ω resistor carrying a steady current of 2 A for 10 s is:Read the answer and worked solution →Estimate the drift speed of electrons in a copper wire carrying 1.5 A with cross-section 1.0×10⁻⁷ m² and n = 8.5×10²⁸ m⁻³ (e = 1.6×10⁻¹⁹ C):Read the answer and worked solution →Two cells, each of emf 1.5 V and internal resistance 0.5 Ω, are connected in series across a 2 Ω resistor. The current through the resistor is:Read the answer and worked solution →Two identical cells, each of emf 1.5 V and internal resistance 0.5 Ω, are connected in parallel across a 1 Ω resistor. The current through the resistor is:Read the answer and worked solution →The maximum current that can be drawn from a cell of emf 1.5 V and internal resistance 0.3 Ω is:Read the answer and worked solution →A Wheatstone bridge is balanced with arms P = 10 Ω, Q = 20 Ω and R = 15 Ω. The unknown resistance S is:Read the answer and worked solution →A 3 Ω resistor is connected in series with a parallel combination of a 6 Ω and a 3 Ω resistor. The equivalent resistance of the network is:Read the answer and worked solution →NEET · Physics · Kirchhoff's LawsRead the answer and worked solution →Ohm's law gives the relation between V, I, R as:Read the answer and worked solution →Resistance R of a wire depends on its length L, area A, and resistivity ρ as:Read the answer and worked solution →Resistivity of a typical metallic conductor as temperature increases:Read the answer and worked solution →Two resistors R₁ and R₂ in SERIES have equivalent resistance:Read the answer and worked solution →Two resistors R₁ and R₂ in PARALLEL have equivalent resistance:Read the answer and worked solution →The drift velocity v_d of conduction electrons is related to current density J (n = number density, e = electron charge) by:Read the answer and worked solution →A galvanometer of resistance G can be converted into a voltmeter of range V by connecting in series a high resistance R given by:Read the answer and worked solution →A cell of emf ε and internal resistance r is connected to an external resistance R. The current is:Read the answer and worked solution →Two 100-W bulbs are connected in series across 220 V. The total power consumed is:Read the answer and worked solution →Kirchhoff's junction rule (KCL) is a consequence of:Read the answer and worked solution →
Worked practice questions
For a uniform wire of resistance R = ρl/A, the resistivity ρ depends on:
- the length of the wire only
- both the length and the area
- the cross-sectional area only
- the material of the wire only
Show answer and solution
Correct answer: D. the material of the wire only
Resistivity is an intrinsic property of the material
R depends on l and A, but ρ does not.
The power dissipated in a resistor of resistance R carrying a steady current I is:
- I²R²
- I / R²
- I²R
- IR
Show answer and solution
Correct answer: C. I²R
Power P = VI = (IR)I = I²R = V²/R.
How to practise
- Choose a Current Electricity question and try to work out your answer.
- Open the question to check the correct answer and read its worked solution.
- Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.
Put it into practice
Continue with Current Electricity practice for NEET UG. Read explanations as you go. No signup form needed to start.
Practise Current Electricity →