| 4901 |
The resistivity of a metal wire depends on: |
Physics
Ohm’s law and resistance |
Easy |
| 4902 |
A metal wire has resistance 10 Ω at 0 °C and temperature coefficient 0.004 °C⁻¹. Its resistance at 100 °C is: |
Physics
Ohm’s law and resistance |
Medium |
| 4903 |
As the temperature of a pure semiconductor rises, its resistivity: |
Physics
Ohm’s law and resistance |
Hard |
| 4904 |
The resistance of the filament of a bulb rated 100 W, 220 V is: |
Physics
Electrical energy and power |
Easy |
| 4905 |
A 100 W, 220 V bulb is connected to a 110 V supply. Assuming constant resistance, it consumes: |
Physics
Electrical energy and power |
Medium |
| 4906 |
A 1000 W heater is used for 3 hours. The energy consumed is: |
Physics
Electrical energy and power |
Easy |
| 4907 |
One kilowatt-hour is equal to: |
Physics
Electrical energy and power |
Medium |
| 4908 |
Electric power is transmitted over long distances at very high voltage mainly because: |
Physics
Electrical energy and power |
Hard |
| 4909 |
A cell of emf 2 V and internal resistance 0.5 Ω is connected to a 3.5 Ω resistor. The terminal voltage is: |
Physics
Cells, emf and internal resistance |
Easy |
| 4910 |
Three identical cells, each of emf 1.5 V and internal resistance 0.5 Ω, are joined in series across a 3 Ω res… |
Physics
Cells, emf and internal resistance |
Medium |
| 4911 |
Two identical cells, each of emf 2 V and internal resistance 1 Ω, are joined in parallel across a 1.5 Ω resis… |
Physics
Cells, emf and internal resistance |
Medium |
| 4912 |
The terminal voltage of a cell equals its emf when: |
Physics
Cells, emf and internal resistance |
Easy |
| 4913 |
A cell of emf E and internal resistance r is being charged by a current I. Its terminal voltage is: |
Physics
Cells, emf and internal resistance |
Hard |
| 4914 |
Kirchhoff’s junction rule is a consequence of the conservation of: |
Physics
Kirchhoff’s rules and the Wheatstone bridge |
Easy |
| 4915 |
Kirchhoff’s loop rule is based on the conservation of: |
Physics
Kirchhoff’s rules and the Wheatstone bridge |
Easy |
| 4916 |
In a Wheatstone bridge, P = 10 Ω, Q = 20 Ω and R = 15 Ω. For balance, S must be: |
Physics
Kirchhoff’s rules and the Wheatstone bridge |
Medium |
| 4917 |
In a meter bridge, a 6 Ω resistor is in the right gap and the unknown resistance in the left gap. The null po… |
Physics
Kirchhoff’s rules and the Wheatstone bridge |
Medium |
| 4918 |
At balance, the condition of a Wheatstone bridge does NOT depend on: |
Physics
Kirchhoff’s rules and the Wheatstone bridge |
Hard |
| 4919 |
Oersted’s experiment first showed that: |
Physics
Biot-Savart law |
Easy |
| 4920 |
A circular loop of radius 0.1 m carries a current of 5 A. The magnetic field at its centre is about: |
Physics
Biot-Savart law |
Medium |
| 4921 |
According to the Biot-Savart law, the field due to a current element is zero at points: |
Physics
Biot-Savart law |
Medium |
| 4922 |
The SI unit of magnetic field B is: |
Physics
Biot-Savart law |
Easy |
| 4923 |
The radius of a current loop is doubled while the current is kept the same. The magnetic field at its centre: |
Physics
Biot-Savart law |
Hard |
| 4924 |
A long straight wire carries a current of 10 A. The magnetic field 5 cm from it is: |
Physics
Ampere’s law |
Easy |
| 4925 |
A long solenoid has 1000 turns per metre and carries 2 A. The field inside it is about: |
Physics
Ampere’s law |
Medium |
| 4926 |
The magnetic field just outside a long ideal solenoid is: |
Physics
Ampere’s law |
Easy |
| 4927 |
The field lines around a long straight current-carrying wire are: |
Physics
Ampere’s law |
Medium |
| 4928 |
The magnetic field at distance r from a long straight wire is B. At distance 3r the field is: |
Physics
Ampere’s law |
Hard |
| 4929 |
A proton moving at 2 × 10⁶ m/s enters a 0.5 T field at right angles. The magnetic force on it is: |
Physics
Force on moving charges and conductors |
Easy |
| 4930 |
Two long parallel wires 0.1 m apart each carry 10 A in the same direction. The force per metre between them i… |
Physics
Force on moving charges and conductors |
Medium |
| 4931 |
A straight wire 0.5 m long carries 3 A at right angles to a uniform field of 0.4 T. The force on the wire is: |
Physics
Force on moving charges and conductors |
Easy |
| 4932 |
The work done by a magnetic field on a moving charged particle is: |
Physics
Force on moving charges and conductors |
Medium |
| 4933 |
A charged particle moves in a circle in a uniform magnetic field. If its speed is doubled, its time period of… |
Physics
Force on moving charges and conductors |
Hard |
| 4934 |
A coil of 50 turns, each of area 0.01 m², carries 2 A. Its magnetic dipole moment is: |
Physics
Current loop as a magnetic dipole |
Easy |
| 4935 |
A galvanometer of resistance 20 Ω gives full-scale deflection at 5 mA. The shunt needed to convert it into a … |
Physics
Current loop as a magnetic dipole |
Medium |
| 4936 |
The same galvanometer (20 Ω, 5 mA full scale) is to be made into a 0–10 V voltmeter. The resistance to be con… |
Physics
Current loop as a magnetic dipole |
Medium |
| 4937 |
A radial magnetic field is used in a moving coil galvanometer so that: |
Physics
Current loop as a magnetic dipole |
Easy |
| 4938 |
A current loop is placed in a uniform magnetic field. The torque on it is maximum when: |
Physics
Current loop as a magnetic dipole |
Hard |
| 4939 |
A bar magnet of moment 2 A m² is placed at 30° to a uniform field of 0.3 T. The torque on it is: |
Physics
Bar magnet and magnetic materials |
Easy |
| 4940 |
Which of the following is diamagnetic? |
Physics
Bar magnet and magnetic materials |
Easy |
| 4941 |
A material has magnetic susceptibility 499. Its relative permeability is: |
Physics
Bar magnet and magnetic materials |
Medium |
| 4942 |
Magnetic field lines of a bar magnet: |
Physics
Bar magnet and magnetic materials |
Medium |
| 4943 |
When a ferromagnetic substance is heated above its Curie temperature, it becomes: |
Physics
Bar magnet and magnetic materials |
Hard |
| 4944 |
The magnetic flux through a 100-turn coil falls from 0.05 Wb to 0.01 Wb in 0.2 s. The average induced emf is: |
Physics
Faraday’s and Lenz’s laws |
Easy |
| 4945 |
A rod 0.2 m long moves at 10 m/s perpendicular to a uniform field of 0.5 T. The emf across its ends is: |
Physics
Faraday’s and Lenz’s laws |
Easy |
| 4946 |
Lenz’s law is a consequence of the law of conservation of: |
Physics
Faraday’s and Lenz’s laws |
Medium |
| 4947 |
The SI unit of magnetic flux is: |
Physics
Faraday’s and Lenz’s laws |
Medium |
| 4948 |
The cores of transformers are laminated mainly to: |
Physics
Faraday’s and Lenz’s laws |
Hard |
| 4949 |
The current in a 0.2 H coil falls uniformly from 5 A to zero in 0.1 s. The average self-induced emf is: |
Physics
Self and mutual induction |
Easy |
| 4950 |
The energy stored in an inductor of 0.2 H carrying 5 A is: |
Physics
Self and mutual induction |
Easy |