Electric Charges and Fields — Physics STD 12 Science — Question

At a place the value of horizontal component of the earth's magnetic field H is 3. A metallic rod AB of length 2 m placed in east-west direction, having the end A towards east, falls vertically downward with a constant velocity of 50 m/s. Which end of the rod becomes positively charged and what is the value of induced potential difference between the two ends

(a) End A, 3	(b) End A, 3 mV
(c) End B, 3	(d) End B, 3 mV

One brass plate is inserted between two charges. The force between two charges will:

Which of the following describe that two lighter atoms combine to form one heavier atom?

On increasing the temperature of a semi-conductor material:

If an object possesses an electric charge, it is said to be electrified or ... A ... When it has no charge, it is said to be ... B ... Here, A and B refer to:

A man runs towards mirror at a speed of 15 m/s. What is the speed of his image

(a) 7.5 m/s

(b) 15 m/s

(c) 30 m/s

(d) 45 m/s

The reading of the ammeter as per figure shown is

(a)

(b)

(c)

(d) 2 A

When a copper voltameter is connected with a battery of e.m.f. 12 volts. 2 gms of copper is deposited in 30 minutes. If the same voltameter is connected across a 6 volt battery, then the mass of copper deposited in 45 minutes would be

(a) 1 gm

(b) 1.5 gm

(c) 2 gm

(d) 2.5 gm

A step-down transformer is connected to 2400 volts line and 80 amperes of current is found to flow in output load. The ratio of the turns in primary and secondary coil is 20 : 1. If transformer efficiency is 100%, then the current flowing in primary coil will be

(a) 1600 A

(b) 20 A

(c) 4 A

(d) 1.5 A

An optically active compound

(a) Rotates the plane polarised light

(b) Changing the direction of polarised light

(c) Do not allow plane polarised light to pass through

(d) None of the above