Current Electricity — Physics STD 12 Science — Question

The waves which are electromagnetic in nature are:

Through two parallel wires A and B, 10 and 2 ampere of currents are passed respectively in opposite direction. If the wire A is infinitely long and the length of the wire B is 2 m, the force on the conductor B, which is situated at 10 cm distance from A will be

(a) 8

(a) 8

(c) 4

(d) 4π

In a transistor:

Two solenoids have identical geometrical construction but one is made of thick wire and the other of thin wire. Which of the following quantities are different for the two solenoids?

The current in a simple series circuit is 5.0 amp. When an additional resistance of 2.0 ohms is inserted, the current drops to 4.0 amp. The original resistance of the circuit in ohms was

(a) 1.25

(b) 8

(c) 10

(d) 20

When the current through the electromagnet of a relay reaches a particular value

The anode of a thermionic diode is connected to the negative terminal of a battery and the cathode to its positive terminal:

1. No appreciable current will pass through the diode.
2. A large current will pass through the diode from the anode to the cathode.
3. A large current will pass through the diode from the cathode to the anode.
4. The diode will be damaged.

Which of the following statement is incorrect

(a) Both ac and dc dynamo have a field magnet

(b) Both ac and dc dynamo have an armature

(c) Both ac and dc dynamo convert mechanical energy into electrical energy

(d) Both ac and dc dynamo have slip rings

To get an output Y=1 from the circuit above, the input must be:

The potential difference applied to an X-ray tube is increased. As a result, in the emitted radiation

(a) The intensity increases

(b) The minimum wavelength increases

(c) The intensity decreases

(d) The minimum wavelength decreases