Electric Charges and Fields — Physics STD 12 Science — Question

A current of 1 ampere is passed through a straight wire of length 2.0 metres. The magnetic field at a point in air at a distance of 3 metres from either end of wire and lying on the axis of wire will be

(a)

(b)

(c)

(d) Zero

The electric potential at a point on the equatorial line of an electric dipole is:

What should be the shape of a conductor that can hold a charge for long?

If 2.2kW power is transmitted through a 100Ω  line at 22,000 V,  the power loss in the form of heat will be

(a) 0.1 W

(b) 1 W

(c) 10 W

(d) 100 W

To increase both the resolving power and magnifying power of a telescope:

If all the resistors shown have the value 2 ohm each, the equivalent resistance over AB is

(a) 2 ohm

(b) 4 ohm

(c) 1

(d) 2

In the given figure the capacitors  have a capacitance 4mF each if the capacitor  has a capacitance 10mF, then effective capacitance between A and B will be

(a) 2mF

(b) 4mF

(c) 6mF

(d) 8mF

A circular loop carrying a current is replaced by an equivalent magnetic dipole. A point on the loop is in:

1. End-on position.
2. Broadside-on position.
3. Both.
4. None.

The gate for which output is high if atleast one input is low?