Collection view working on both iphone but half showing in ipad - ios

Question

In my application,I am using Collection view as i'd take in Xib.now there is image of array come from server side. And they are correctly seen in both iphone 3.5 and 4 inch screen.But when i select device as ipad it seem like this:
There are three rows appear and i don't know how to solve this problem.I want only one row which will be scrollable.
Here is my code:
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 1;
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return [imagArr count];
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
QBAssetsCollectionViewCell *cell = (QBAssetsCollectionViewCell *)[collectionView dequeueReusableCellWithReuseIdentifier:#"QBAssetsCollectionViewCell" forIndexPath:indexPath];
NSDictionary *imageName = [[imagArr objectAtIndex:indexPath.row] objectForKey:#"Content"];
NSString *sr = [imageName objectForKey:#"text"];
cell.Img.image = [self decodeBase64ToImage:sr];
//[cell updateCell];
return cell;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"%ld",(long)indexPath.row);
NSDictionary *imageName = [[imagArr objectAtIndex:indexPath.row] objectForKey:#"Content"];
NSString *sr = [imageName objectForKey:#"text"];
cloud.image= [self decodeBase64ToImage:sr];
[self.collectionView setHidden:YES];
}