When a current passes through a wire whose different parts are maintained at different temperatures, evolution or absorption of heat all along the length of wire is known as
|
(a) Joule effect |
(b) Seebeck effect |
(c) Peltier effect |
(d) Thomson effect |
(d) Thomson effect
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
In a metre bridge experiment null point is obtained at 20 cm from one end of the wire when resistance X is balanced against another resistance Y. If X < Y, then where will be the new position of the null point from the same end, if one decides to balance a resistance of 4X against Y
|
(a) 50 cm |
(b) 80 cm |
(c) 40 cm |
(d) 70 cm |
If a 2 kW boiler is used everyday for 1 hour, then electrical energy consumed by boiler in thirty days is
|
(a) 15 unit |
(b) 60 unit |
(c) 120 unit |
(d) 240 unit |
Which of the following statement is wrong
|
(a) Voltmeter should have high resistance |
|
(b) Ammeter should have low resistance |
|
(c) Ammeter is placed in parallel across the conductor in a circuit |
|
(d) Voltmeter is placed in parallel across the conductor in a circuit |
A semiconductor device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops almost to zero. The device may be
| (a) A P-type semiconductor | (b) An N-type semiconductor |
| (c) A PN-junction | (d) An intrinsic semiconductor |
When yellow light is incident on a surface, no electrons are emitted while green light can emit. If red light is incident on the surface, then
|
(a) No electrons are emitted |
|
(b) Photons are emitted |
|
(c) Electrons of higher energy are emitted |
|
(d) Electrons of lower energy are emitted |